Date & time
Convert timestamps and time zones, compare dates and work with calendar formats.
20 tools in this category. Every tool runs in the browser and needs no sign-up.
Snowflake ID Decoder
Decode a 64-bit Snowflake ID into its timestamp, worker, process and sequence fields.
Unix Timestamp Converter
Live Unix clock and three converters: timestamp to date, date string to timestamp, and separate date fields, with seconds or milliseconds.
Business Day Calculator
Count Monday–Friday, excluding your listed holidays. No regional holiday calendar or weekend make-up workdays are assumed.
Date Difference Calculator
Count calendar days between two dates, with an option to include both endpoints. Leap years are handled automatically.
Age Calculator
Calculate completed years of age on a chosen reference date, including birthdays and leap-day births.
Duration Calculator
Add or subtract durations in HH:MM:SS format, including values longer than 24 hours and negative results.
Batch Timestamp Converter
Convert lines of Unix seconds or milliseconds to ISO dates, or reverse the conversion.
Timestamp Unit Converter
Convert seconds, milliseconds, microseconds and nanoseconds without integer precision loss.
Timestamp Difference Calculator
Subtract timestamp A from B and show the exact difference in the selected unit and seconds.
Time Zone Converter
Convert an ISO instant with an explicit offset into an IANA time zone.
Add / Subtract from Date
Add signed years, months, days, hours, minutes or seconds to an ISO instant.
ISO Week Date Converter
Convert Gregorian dates to ISO week-year, week and weekday and back.
Day of Year Converter
Convert dates to year-and-ordinal-day notation or restore dates from ordinal days.
Excel Serial Date Converter
Convert Excel serial dates in the 1900 or 1904 system to ISO UTC and back.
Windows FILETIME Converter
Convert Windows FILETIME 100-nanosecond ticks to ISO UTC and back without losing the sub-millisecond part.
Unix Timestamp Converter
Convert Unix seconds or milliseconds to UTC dates and ISO dates back to timestamps.
Cron Expression Generator & Explainer — Next Run Times
Build or paste a five-field cron expression, read it in plain language and see the next 10 run times in your time zone. Presets cover common schedules.
Countdown timer
Free online countdown timer with alarm: 1–60 minute presets or any hours, minutes and seconds. Stays accurate in background tabs, shows time in the tab title.
Stopwatch
Free online stopwatch with laps and hundredths of a second. Space starts/stops, L records a lap, R resets. Highlights fastest/slowest laps, copy as CSV.
Pomodoro timer
Free online Pomodoro timer: 25-minute focus sessions, 5-minute short breaks and a 15-minute long break every 4 rounds. Adjustable, with chime and auto-start.