randarium
Dates

Random Datetime Generator

Draw random datetimes and format them as ISO, Unix timestamps, or readable UTC text.

Also known as: random timestamp

seeded

Output

No output yet — set your options and hit .
About this tool, tips & examples

What it does

The Random Datetime Generator draws random timestamps from any datetime range and formats them as ISO 8601, Unix seconds, or readable UTC text — with an optional timezone marker. It’s the full-timestamp counterpart to the Random Date tool: for created_at columns, event logs, and anything that needs time-of-day, not just the day.

Common use cases

  • Event log fixtures — timestamps scattered through a window for testing time-ordered displays and queries.
  • API fixtures — ISO 8601 values for request/response examples and contract tests.
  • Unix timestamp testing — integer-seconds values for systems that store epoch time, including conversion-boundary checks.
  • Time-window logic — data spread across a range exercises bucketing, pagination-by-time, and retention rules.

Settings

  • Start / End datetime — the inclusive range; inputs with explicit offsets are interpreted correctly.
  • Format — ISO 8601, Unix seconds, or readable UTC text.
  • Include timezone — show the UTC marker on formatted output.
  • How many — batch generation for bulk fixtures.
  • Seed — the same seed and settings regenerate identical timestamps.

Privacy note

Timestamps are generated locally in your browser and never uploaded. They’re synthetic — random instants, not records of real events.

FAQ

What timezone is the output in? Everything normalizes to UTC — the sane fixture convention, since UTC sorts, compares, and converts without surprises. Local rendering is your display layer’s job.

ISO or Unix — which should I use? ISO 8601 for anything human-visible or JSON-carried; Unix seconds for epoch-based systems. Generating both from the same seed gives you matched pairs for conversion tests.

Are the timestamps ordered? Draws are independent — sort them yourself if the fixture needs chronology, or see the Event Stream generator for inherently ordered event data.