ISO 8601 timestamps emitted with different precision in Python vs Node #22

Closed
#39
Closed
ISO 8601 timestamps emitted with different precision in Python vs Node#22
#39

Description

@AndresL230
AndresL230
opened on May 13, 2026

ISO 8601 timestamps emitted with different precision in Python vs Node

Severity: Medium
Affected repos:middleware-python, middleware-node, api
Component boundary: middleware → API telemetry

Symptom

  • Python emits datetime.now(timezone.utc).isoformat() → microsecond precision with +00:00 suffix: "2026-05-13T14:30:45.123456+00:00".
  • Node emits new Date().toISOString() → millisecond precision with Z suffix: "2026-05-13T14:30:45.123Z".

The API stores windowStart and windowEnd and later compares across SDKs in rollups. Sorting and grouping still work (ISO 8601 collation), but anyone who joins on equality, parses with a fixed format, or computes deltas across SDKs has to handle the shape difference.

Evidence

  • middleware-python/recost/_aggregator.py — datetime.now(timezone.utc).isoformat().
  • middleware-node/src/core/aggregator.ts — new Date().toISOString().

Impact

  • Inconsistent wire format. Cosmetic in most analyses; potentially a sharp edge in any future code that does exact-string compare or parses with a tighter format.

Fix recommendation

Normalize both to millisecond-precision Z format (matches Node, which is more compact):

# Pythondef_iso_now() ->str:
returndatetime.now(timezone.utc).isoformat(timespec="milliseconds").replace("+00:00", "Z")

Verification

  • Python and Node SDKs emit identical timestamp string formats for the same instant (within ms).

Related

Parity with recost-dev/middleware-node#20. Python is the side that should change to match Node's millisecond-Z format.

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      , 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
       blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

      Skip to content
      ISO 8601 timestamps emitted with different precision in Python vs Node #22
      Closed
      #39
      Closed
      ISO 8601 timestamps emitted with different precision in Python vs Node#22
      #39
      Description
      @AndresL230
      AndresL230
      opened on May 13, 2026
      ISO 8601 timestamps emitted with different precision in Python vs Node
      Severity: Medium
      Affected repos:middleware-python, middleware-node, api
      Component boundary: middleware → API telemetry
      Symptom
      • Python emits datetime.now(timezone.utc).isoformat() → microsecond precision with +00:00 suffix: "2026-05-13T14:30:45.123456+00:00".
      • Node emits new Date().toISOString() → millisecond precision with Z suffix: "2026-05-13T14:30:45.123Z".
      The API stores windowStart and windowEnd and later compares across SDKs in rollups. Sorting and grouping still work (ISO 8601 collation), but anyone who joins on equality, parses with a fixed format, or computes deltas across SDKs has to handle the shape difference.
      Evidence
      • middleware-python/recost/_aggregator.py — datetime.now(timezone.utc).isoformat().
      • middleware-node/src/core/aggregator.ts — new Date().toISOString().
      Impact
      • Inconsistent wire format. Cosmetic in most analyses; potentially a sharp edge in any future code that does exact-string compare or parses with a tighter format.
      Fix recommendation
      Normalize both to millisecond-precision Z format (matches Node, which is more compact):
      # Pythondef_iso_now() ->str:
returndatetime.now(timezone.utc).isoformat(timespec="milliseconds").replace("+00:00", "Z")
      Verification
      • Python and Node SDKs emit identical timestamp string formats for the same instant (within ms).
      Related
      Parity with recost-dev/middleware-node#20. Python is the side that should change to match Node's millisecond-Z format.
      Metadata
      Metadata
      Assignees
      No one assigned
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        No labels
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        No type
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        No projects
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          No milestone
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          None yet
          Development
          No branches or pull requests
          Issue actions
          
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

          Skip to content
          ISO 8601 timestamps emitted with different precision in Python vs Node #22
          Closed
          #39
          Closed
          ISO 8601 timestamps emitted with different precision in Python vs Node#22
          #39
          Description
          @AndresL230
          AndresL230
          opened on May 13, 2026
          ISO 8601 timestamps emitted with different precision in Python vs Node
          Severity: Medium
          Affected repos:middleware-python, middleware-node, api
          Component boundary: middleware → API telemetry
          Symptom
          • Python emits datetime.now(timezone.utc).isoformat() → microsecond precision with +00:00 suffix: "2026-05-13T14:30:45.123456+00:00".
          • Node emits new Date().toISOString() → millisecond precision with Z suffix: "2026-05-13T14:30:45.123Z".
          The API stores windowStart and windowEnd and later compares across SDKs in rollups. Sorting and grouping still work (ISO 8601 collation), but anyone who joins on equality, parses with a fixed format, or computes deltas across SDKs has to handle the shape difference.
          Evidence
          • middleware-python/recost/_aggregator.py — datetime.now(timezone.utc).isoformat().
          • middleware-node/src/core/aggregator.ts — new Date().toISOString().
          Impact
          • Inconsistent wire format. Cosmetic in most analyses; potentially a sharp edge in any future code that does exact-string compare or parses with a tighter format.
          Fix recommendation
          Normalize both to millisecond-precision Z format (matches Node, which is more compact):
          # Pythondef_iso_now() ->str:
returndatetime.now(timezone.utc).isoformat(timespec="milliseconds").replace("+00:00", "Z")
          Verification
          • Python and Node SDKs emit identical timestamp string formats for the same instant (within ms).
          Related
          Parity with recost-dev/middleware-node#20. Python is the side that should change to match Node's millisecond-Z format.
          Metadata
          Metadata
          Assignees
          No one assigned
            Labels
            No labels
            No labels
            Type
            No type
            Projects
            No projects
              Milestone
              No milestone
              Relationships
              None yet
              Development
              No branches or pull requests
              Issue actions
              
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

              Skip to content
              ISO 8601 timestamps emitted with different precision in Python vs Node #22
              Closed
              #39
              Closed
              ISO 8601 timestamps emitted with different precision in Python vs Node#22
              #39
              Description
              @AndresL230
              AndresL230
              opened on May 13, 2026
              ISO 8601 timestamps emitted with different precision in Python vs Node
              Severity: Medium
              Affected repos:middleware-python, middleware-node, api
              Component boundary: middleware → API telemetry
              Symptom
              • Python emits datetime.now(timezone.utc).isoformat() → microsecond precision with +00:00 suffix: "2026-05-13T14:30:45.123456+00:00".
              • Node emits new Date().toISOString() → millisecond precision with Z suffix: "2026-05-13T14:30:45.123Z".
              The API stores windowStart and windowEnd and later compares across SDKs in rollups. Sorting and grouping still work (ISO 8601 collation), but anyone who joins on equality, parses with a fixed format, or computes deltas across SDKs has to handle the shape difference.
              Evidence
              • middleware-python/recost/_aggregator.py — datetime.now(timezone.utc).isoformat().
              • middleware-node/src/core/aggregator.ts — new Date().toISOString().
              Impact
              • Inconsistent wire format. Cosmetic in most analyses; potentially a sharp edge in any future code that does exact-string compare or parses with a tighter format.
              Fix recommendation
              Normalize both to millisecond-precision Z format (matches Node, which is more compact):
              # Pythondef_iso_now() ->str:
returndatetime.now(timezone.utc).isoformat(timespec="milliseconds").replace("+00:00", "Z")
              Verification
              • Python and Node SDKs emit identical timestamp string formats for the same instant (within ms).
              Related
              Parity with recost-dev/middleware-node#20. Python is the side that should change to match Node's millisecond-Z format.
              Metadata
              Metadata
              Assignees
              No one assigned
                Labels
                No labels
                No labels
                Type
                No type
                Projects
                No projects
                  Milestone
                  No milestone
                  Relationships
                  None yet
                  Development
                  No branches or pull requests
                  Issue actions
                  
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

                  Skip to content
                  ISO 8601 timestamps emitted with different precision in Python vs Node #22
                  Closed
                  #39
                  Closed
                  ISO 8601 timestamps emitted with different precision in Python vs Node#22
                  #39
                  Description
                  @AndresL230
                  AndresL230
                  opened on May 13, 2026
                  ISO 8601 timestamps emitted with different precision in Python vs Node
                  Severity: Medium
                  Affected repos:middleware-python, middleware-node, api
                  Component boundary: middleware → API telemetry
                  Symptom
                  • Python emits datetime.now(timezone.utc).isoformat() → microsecond precision with +00:00 suffix: "2026-05-13T14:30:45.123456+00:00".
                  • Node emits new Date().toISOString() → millisecond precision with Z suffix: "2026-05-13T14:30:45.123Z".
                  The API stores windowStart and windowEnd and later compares across SDKs in rollups. Sorting and grouping still work (ISO 8601 collation), but anyone who joins on equality, parses with a fixed format, or computes deltas across SDKs has to handle the shape difference.
                  Evidence
                  • middleware-python/recost/_aggregator.py — datetime.now(timezone.utc).isoformat().
                  • middleware-node/src/core/aggregator.ts — new Date().toISOString().
                  Impact
                  • Inconsistent wire format. Cosmetic in most analyses; potentially a sharp edge in any future code that does exact-string compare or parses with a tighter format.
                  Fix recommendation
                  Normalize both to millisecond-precision Z format (matches Node, which is more compact):
                  # Pythondef_iso_now() ->str:
returndatetime.now(timezone.utc).isoformat(timespec="milliseconds").replace("+00:00", "Z")
                  Verification
                  • Python and Node SDKs emit identical timestamp string formats for the same instant (within ms).
                  Related
                  Parity with recost-dev/middleware-node#20. Python is the side that should change to match Node's millisecond-Z format.
                  Metadata
                  Metadata
                  Assignees
                  No one assigned
                    Labels
                    No labels
                    No labels
                    Type
                    No type
                    Projects
                    No projects
                      Milestone
                      No milestone
                      Relationships
                      None yet
                      Development
                      No branches or pull requests
                      Issue actions
                      
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

                      Skip to content
                      ISO 8601 timestamps emitted with different precision in Python vs Node #22
                      Closed
                      #39
                      Closed
                      ISO 8601 timestamps emitted with different precision in Python vs Node#22
                      #39
                      Description
                      @AndresL230
                      AndresL230
                      opened on May 13, 2026
                      ISO 8601 timestamps emitted with different precision in Python vs Node
                      Severity: Medium
                      Affected repos:middleware-python, middleware-node, api
                      Component boundary: middleware → API telemetry
                      Symptom
                      • Python emits datetime.now(timezone.utc).isoformat() → microsecond precision with +00:00 suffix: "2026-05-13T14:30:45.123456+00:00".
                      • Node emits new Date().toISOString() → millisecond precision with Z suffix: "2026-05-13T14:30:45.123Z".
                      The API stores windowStart and windowEnd and later compares across SDKs in rollups. Sorting and grouping still work (ISO 8601 collation), but anyone who joins on equality, parses with a fixed format, or computes deltas across SDKs has to handle the shape difference.
                      Evidence
                      • middleware-python/recost/_aggregator.py — datetime.now(timezone.utc).isoformat().
                      • middleware-node/src/core/aggregator.ts — new Date().toISOString().
                      Impact
                      • Inconsistent wire format. Cosmetic in most analyses; potentially a sharp edge in any future code that does exact-string compare or parses with a tighter format.
                      Fix recommendation
                      Normalize both to millisecond-precision Z format (matches Node, which is more compact):
                      # Pythondef_iso_now() ->str:
returndatetime.now(timezone.utc).isoformat(timespec="milliseconds").replace("+00:00", "Z")
                      Verification
                      • Python and Node SDKs emit identical timestamp string formats for the same instant (within ms).
                      Related
                      Parity with recost-dev/middleware-node#20. Python is the side that should change to match Node's millisecond-Z format.
                      Metadata
                      Metadata
                      Assignees
                      No one assigned
                        Labels
                        No labels
                        No labels
                        Type
                        No type
                        Projects
                        No projects
                          Milestone
                          No milestone
                          Relationships
                          None yet
                          Development
                          No branches or pull requests
                          Issue actions
                          
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

                          Skip to content
                          ISO 8601 timestamps emitted with different precision in Python vs Node #22
                          Closed
                          #39
                          Closed
                          ISO 8601 timestamps emitted with different precision in Python vs Node#22
                          #39
                          Description
                          @AndresL230
                          AndresL230
                          opened on May 13, 2026
                          ISO 8601 timestamps emitted with different precision in Python vs Node
                          Severity: Medium
                          Affected repos:middleware-python, middleware-node, api
                          Component boundary: middleware → API telemetry
                          Symptom
                          • Python emits datetime.now(timezone.utc).isoformat() → microsecond precision with +00:00 suffix: "2026-05-13T14:30:45.123456+00:00".
                          • Node emits new Date().toISOString() → millisecond precision with Z suffix: "2026-05-13T14:30:45.123Z".
                          The API stores windowStart and windowEnd and later compares across SDKs in rollups. Sorting and grouping still work (ISO 8601 collation), but anyone who joins on equality, parses with a fixed format, or computes deltas across SDKs has to handle the shape difference.
                          Evidence
                          • middleware-python/recost/_aggregator.py — datetime.now(timezone.utc).isoformat().
                          • middleware-node/src/core/aggregator.ts — new Date().toISOString().
                          Impact
                          • Inconsistent wire format. Cosmetic in most analyses; potentially a sharp edge in any future code that does exact-string compare or parses with a tighter format.
                          Fix recommendation
                          Normalize both to millisecond-precision Z format (matches Node, which is more compact):
                          # Pythondef_iso_now() ->str:
returndatetime.now(timezone.utc).isoformat(timespec="milliseconds").replace("+00:00", "Z")
                          Verification
                          • Python and Node SDKs emit identical timestamp string formats for the same instant (within ms).
                          Related
                          Parity with recost-dev/middleware-node#20. Python is the side that should change to match Node's millisecond-Z format.
                          Metadata
                          Metadata
                          Assignees
                          No one assigned
                            Labels
                            No labels
                            No labels
                            Type
                            No type
                            Projects
                            No projects
                              Milestone
                              No milestone
                              Relationships
                              None yet
                              Development
                              No branches or pull requests
                              Issue actions
                              
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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                              ISO 8601 timestamps emitted with different precision in Python vs Node #22
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                              #39
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                              ISO 8601 timestamps emitted with different precision in Python vs Node#22
                              #39
                              Description
                              @AndresL230
                              AndresL230
                              opened on May 13, 2026
                              ISO 8601 timestamps emitted with different precision in Python vs Node
                              Severity: Medium
                              Affected repos:middleware-python, middleware-node, api
                              Component boundary: middleware → API telemetry
                              Symptom
                              • Python emits datetime.now(timezone.utc).isoformat() → microsecond precision with +00:00 suffix: "2026-05-13T14:30:45.123456+00:00".
                              • Node emits new Date().toISOString() → millisecond precision with Z suffix: "2026-05-13T14:30:45.123Z".
                              The API stores windowStart and windowEnd and later compares across SDKs in rollups. Sorting and grouping still work (ISO 8601 collation), but anyone who joins on equality, parses with a fixed format, or computes deltas across SDKs has to handle the shape difference.
                              Evidence
                              • middleware-python/recost/_aggregator.py — datetime.now(timezone.utc).isoformat().
                              • middleware-node/src/core/aggregator.ts — new Date().toISOString().
                              Impact
                              • Inconsistent wire format. Cosmetic in most analyses; potentially a sharp edge in any future code that does exact-string compare or parses with a tighter format.
                              Fix recommendation
                              Normalize both to millisecond-precision Z format (matches Node, which is more compact):
                              # Pythondef_iso_now() ->str:
returndatetime.now(timezone.utc).isoformat(timespec="milliseconds").replace("+00:00", "Z")
                              Verification
                              • Python and Node SDKs emit identical timestamp string formats for the same instant (within ms).
                              Related
                              Parity with recost-dev/middleware-node#20. Python is the side that should change to match Node's millisecond-Z format.
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