Spec clarification: Timestamps should explicitly require UTC indicator

[mwiesen]

Summary

The SPXP specification states that timestamps are in UTC, but the examples and actual implementations use timestamps without the Z suffix (or +00:00), which can lead to ambiguity.

Current Behavior

The spec says timestamps are UTC, but examples show:

{
  "seqts": "2018-09-17T14:04:27.373",
  "createts": "2018-09-16T12:23:18.751"
}

Problem

Without an explicit timezone indicator, parsers may interpret these as local time:

// Ambiguous - could be parsed as local time
new Date('2018-09-17T14:04:27.373')

// Explicit UTC - no ambiguity
new Date('2018-09-17T14:04:27.373Z')

This can cause issues when:

• Clients are in different timezones
• Sorting posts chronologically
• Displaying "posted X hours ago" relative times

Suggestion

Clarify in the spec that timestamps:

1. MUST be in UTC (already stated)
2. SHOULD include the Z suffix for ISO 8601 compliance

Example:

{
  "seqts": "2018-09-17T14:04:27.373Z",
  "createts": "2018-09-16T12:23:18.751Z"
}

Alternatively, explicitly state that the absence of a timezone indicator implies UTC, so client implementations know to handle it correctly.

References

• ISO 8601 - UTC times should end with Z
• RFC 3339 - Internet date/time format

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Discovered while building a browser-based SPXP profile viewer.