Apus uses the configured user timezone for message envelopes, system events, and the system prompt. When agents.defaults.userTimezone is unset, those surfaces use the host timezone. Provider timestamps are preserved so tools keep their native semantics. When the agent needs the exact current time and session_status is available, it runs that tool.

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

Envelope timestamps use agents.defaults.userTimezone when configured, otherwise the host timezone. Absolute timestamps and elapsed-time suffixes are built in.

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:

[WhatsApp +1555 +30s Sun 2026-01-18 00:20:12 CST] follow-up

System prompt: temporal context

The system prompt includes a volatile Temporal Context section with the local calendar date and time zone, but no live clock:

Current date: 2026-01-05
Time zone: America/Chicago

The zone is agents.defaults.userTimezone when configured, otherwise the host timezone. The section lives below the prompt-cache boundary, so date rollover and timezone changes do not invalidate the stable prefix. When available, session_status remains the source for exact current time.

System event lines (local by default)

Queued system events inserted into agent context use agents.defaults.userTimezone when configured, otherwise the host timezone.

System: [2026-01-12 12:19:17 PST] Model switched.

Configure user timezone

{
  agents: {
    defaults: {
      userTimezone: "America/Chicago",
    },
  },
}

Time format detection

Rendered clock values follow the operating system and locale preference. Apus detects 12-hour or 24-hour display on macOS and Windows, then falls back to locale formatting. The detected value is cached per process.

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

Channel tools return provider-native timestamps and add normalized fields for consistency:

Raw provider fields are preserved so nothing is lost.

If you need local time, convert it downstream using the known timezone.

Related docs