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OpenClaw uses host-local time for transport timestamps and puts only the time zone in the system prompt. Provider timestamps are preserved so tools keep their native semantics. When the agent needs the current time, it runs the session_status tool.

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Message envelopes (local by default)

Inbound messages are wrapped with a weekday plus second-precision timestamp: 
[WhatsApp +1555 Mon 2026-01-05 16:26:34 PST] message text
The envelope timestamp is host-local by default, regardless of the provider timezone. Override under agents.defaults: 
{
  agents: {
    defaults: {
      envelopeTimezone: "local", // "utc" | "local" | "user" | IANA timezone
      envelopeTimestamp: "on", // "on" | "off"
      envelopeElapsed: "on", // "on" | "off"
    },
  },
}
KeyValuesBehavior
envelopeTimezonelocal (default), utc, user, explicit IANA nameuser uses agents.defaults.userTimezone (host timezone when unset). An explicit IANA name (e.g. "America/Chicago") pins a fixed zone; unrecognized names fall back to UTC.
envelopeTimestampon (default), offoff removes absolute timestamps from envelope headers, direct agent prompt prefixes, and embedded model-input prefixes.
envelopeElapsedon (default), offoff removes the elapsed-time suffix (the +30s / +2m style) shown since the previous message in the session.

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Examples

Local (default): 
[WhatsApp +1555 Sun 2026-01-18 00:19:42 PST] hello
User timezone: 
[WhatsApp +1555 Sun 2026-01-18 00:19:42 CST] hello
Elapsed time with envelopeTimezone: "utc": 
[WhatsApp +1555 +30s Sun 2026-01-18T05:19:00Z] follow-up

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System prompt: current date and time

The system prompt includes a Current Date & Time section with the time zone only (no clock or time format) so prompt caching stays stable: 
Time zone: America/Chicago
The zone is agents.defaults.userTimezone when configured, otherwise the host timezone. The prompt also instructs the agent to run the session_status tool whenever it needs the current date, time, or day of week.

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System event lines (local by default)

Queued system events inserted into agent context are prefixed with a timestamp using the same envelopeTimezone selection as message envelopes (default: host-local). 
System: [2026-01-12 12:19:17 PST] Model switched.

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Configure user timezone + format

{
  agents: {
    defaults: {
      userTimezone: "America/Chicago",
      timeFormat: "auto", // auto | 12 | 24
    },
  },
}
  • userTimezone sets the user-local timezone for prompt context (and for envelopeTimezone: "user").
  • timeFormat controls 12h/24h display in prompt-facing times. auto follows OS preferences.

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Time format detection (auto)

When timeFormat: "auto", OpenClaw inspects the OS preference (macOS and Windows) and falls back to locale formatting. The detected value is cached per process to avoid repeated system calls.

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Tool payloads + connectors (raw provider time + normalized fields)

Channel tools return provider-native timestamps and add normalized fields for consistency:
  • timestampMs: epoch milliseconds (UTC)
  • timestampUtc: ISO 8601 UTC string
Raw provider fields are preserved so nothing is lost.
  • Discord: UTC ISO timestamps
  • Slack: epoch-like strings from the API
  • Telegram/WhatsApp: provider-specific numeric/ISO timestamps
If you need local time, convert it downstream using the known timezone.