Free, browser-based utilities for everyday developer workflows

Timezone / Date Math Calculator

Convert times across time zones, calculate date offsets and business days, parse ISO durations, and inspect date ranges.

  • Translate release, incident, or meeting times between common IANA time zones.
  • Apply day, week, month, or business-day offsets to a base date.
  • Parse ISO 8601 durations and compare date ranges in one place.

Use cases

Convert Time Between Time Zones

Explore more in the Use cases library.

One tool for wall-clock conversions, offset calculations, and ISO duration parsing.

Timezone conversion

Naive values such as 2026-04-04 15:30 are interpreted in the source time zone you provide.

Output

How to use Timezone / Date Math Calculator

Enter a date/time and source or target time zone for conversion, then switch tabs when you need business-day offsets or ISO duration parsing. The output stays text-first so you can drop it directly into tickets, runbooks, or deployment notes.

Common use cases

Developers use it to translate release windows across regions, analysts calculate business-day deadlines, and incident responders compare event ranges and durations when building timelines.

Why run this in your browser?

All calculations happen locally in your browser. Date strings, schedules, and internal timelines stay on your machine instead of being copied into an external service.