Free Online Time Tools
Olutil stands for Online Utilities — a growing suite of privacy-first, browser-native web tools. This sub-site brings you a complete suite of time utilities that run entirely in your browser: Unix timestamp converters, date difference calculators, timezone converters, world clocks, countdown timers and more, all in one place. 100% Local Processing
Timestamp Converters
Unix Timestamp to Date
Convert Unix timestamps to human-readable dates. Supports seconds, milliseconds, microseconds and nanoseconds. Free online conv...
Epoch Converter
Convert Unix epoch time to human-readable dates and back. Shows seconds, milliseconds, ISO 8601, RFC 2822 and comparison with f...
Date to Unix Timestamp
Convert a date or datetime string into Unix seconds, milliseconds, microseconds or nanoseconds. Runs in your browser, nothing i...
Current Unix Timestamp
Live current Unix timestamp with millisecond precision. Updates automatically and shows ISO 8601, RFC 2822 and local time. Free...
Timestamp to ISO 8601
Convert Unix timestamps to ISO 8601, RFC 3339 and RFC 2822 strings. Pick any IANA timezone for the offset. Free online converte...
ISO 8601 to Timestamp
Convert ISO 8601, RFC 3339 and RFC 2822 strings to Unix seconds, milliseconds, microseconds and nanoseconds. Instant, in-browse...
Timestamp to UTC
Convert any Unix timestamp to UTC, your local time and any IANA timezone at once, with the exact offset difference in hours. Fr...
Timestamp Generator
Generate the current or any specified time as Unix seconds, milliseconds, microseconds and nanoseconds. Exact integers, plus IS...
Date Calculators
Date Calculator
Calculate the exact difference between two dates in days, weeks, months and years. Shows the calendar difference and total hour...
Date Difference Calculator
Difference between two dates with inclusive day counts, working days, non-working days, excluded public holidays and total week...
Business Days Calculator
Count working days between two dates. Customisable rest days, public holiday exclusions, calendar days and weekly workdays. Fre...
Add Days to Date
Add or subtract days, weeks, months, years, hours, minutes and seconds from any date. Shows the result in ISO 8601, RFC 2822 an...
Day of the Week Calculator
Find the weekday of any date, with ISO weekday number, day of year, ISO week and the first weekday of the month. Free online da...
Week Number Calculator
Find the ISO 8601 week number, ISO week date, US week number, day of year, quarter and leap year status of any date. Free onlin...
Leap Year Checker
Check if any year is a leap year under the Gregorian rules, with the century exception explained. Shows day counts and nearby l...
Age Calculator
Calculate exact age in years, months and days from a birth date, with total months, weeks, days and hours, plus your next birth...
Next Birthday Calculator
Live countdown to your next birthday. Shows days remaining, the date, your current age and today clock, updating every second. ...
Date Range Generator
List every date between two dates with a custom step: daily, weekly, monthly or yearly. Shows count and calendar span. Free onl...
Random Date Generator
Generate random dates between two bounds in five formats: YYYY-MM-DD, US or European order, ISO with time, or Unix seconds. Fre...
Time Zone Tools
Time Zone Converter
Convert the current time or any specific time between two timezones. 50 world cities, exact offset difference, DST handled auto...
UTC to Local Time
Convert UTC or GMT time to your local time. Shows the local date, whether the day shifts across midnight, your offset and Unix ...
World Clock
Live world clock showing the current time in 50 cities with dates, weekdays and UTC offsets. Updates every second, searchable, ...
Time Difference Calculator
Calculate the exact time difference between two timezones on any date. Shows both offsets, the gap in hours, weekdays and wheth...
Meeting Planner
Pick a meeting time in any timezone and see the matching wall clock time in every selected city. Perfect for cross-timezone tea...
Timezone Offset Calculator
Calculate the UTC offset of any timezone on any date, in hours and minutes, plus the standard and DST offsets of the zone. Free...
DST Checker
Check whether daylight saving time is active in any timezone on any date. Shows the offset, the standard offset and when DST ap...
Timers & Countdowns
Online Stopwatch
Online stopwatch with 10 millisecond precision and split lap recording. Start, pause, resume and reset without losing your plac...
Online Countdown Timer
Free online countdown timer with hours, minutes and seconds, quick presets and a live progress bar. Alerts you when time is up....
Pomodoro Timer
Pomodoro timer with work sessions, short and long breaks, and automatic cycling. Customise minutes and session count. Free focu...
Countdown Calculator
Live countdown to any date or event. Shows days, hours, minutes and seconds remaining, updating every 250 milliseconds. Counts ...
Analog World Clock
Compact analog world clock for 50 cities in a dense grid. Pin any city to a top row that stays visible, with live hands, dates ...
Formatting & Converters
Date Formatter
Format any date with your own pattern. Tokens for year, month, day, week, day of year, weekday and offset. Presets included, ru...
Seconds to HH:MM:SS
Convert seconds to HH:MM:SS with days and hours broken out for long durations. Handles fractions and totals. Free online second...
HH:MM:SS to Seconds
Convert a HH:MM:SS or H:MM:SS duration string to total seconds, minutes and hours. Handles hours above 24. Free online time con...
Time Unit Converter
Convert time between seconds, minutes, hours, days, weeks, months and years. Shows every unit in one conversion. Free online ti...
ISO 8601 Duration Converter
Parse ISO 8601 durations like P1Y2M3DT4H5M6S into total seconds, minutes, hours and days, or build an ISO duration from a plain...
Excel Date Converter
Convert between Excel serial numbers and real dates. Handles the 1900 leap year bug, the 1904 Mac system, and time fractions in...
Julian Date Converter
Convert between Julian Date, Modified Julian Date and normal calendar dates. Astronomical continuous day count, accurate to the...
GPS Time Converter
Convert Unix time to GPS time, GPS week number, NTP 64 bit timestamp and TAI. Includes the 37 second leap offset and NTP hex fr...
HTTP Date Formatter
Format HTTP date headers like Sun, 06 Nov 1994 08:49:37 GMT. Convert between HTTP dates, ISO 8601, Unix timestamps and local ti...
Cookie Expiry Calculator
Calculate cookie expiration from a session length or an exact date. Get the Expires header, Max-Age seconds and a ready Set-Coo...
Calendars & Clocks
Hijri Date Converter
Convert between the Gregorian and Hijri Islamic calendars using the Umm al-Qura system. Both directions, with weekday and month...
Hebrew Date Converter
Convert any Gregorian date to the Hebrew calendar with weekday, month and Hebrew year. Uses the browser calendar engine, runs l...
Moon Phase Calculator
Calculate the moon phase for any date: new moon, full moon, quarters and crescents, with age, illumination and next moon events...
Sunrise Sunset Calculator
Estimate sunrise and sunset times for any city and date using latitude and longitude. Includes daylight length. Free online sun...
Roman Numeral Date Converter
Convert dates to and from Roman numerals, e.g. 20.IX.MMXXVI. Supports both directions and any year 1-3999. Free online date con...
Swatch Internet Time
Live Swatch Internet Time in beats, with UTC and your local time. @000.000 format updates in real time. Free online .beat clock.
Binary Clock
Live binary clock: hours, minutes and seconds rendered as glowing LED columns. Read the time visually or hit decode. Free onlin...
Decimal Time Converter
Live decimal time where a day is 100,000 units, plus a converter between decimal time and normal HH:MM:SS. Free online decimal ...
Cron & Scheduling
Work Time Tools
Work Hours Calculator
Calculate net work hours between a start and end time, minus breaks, and multiply for any number of work days. Free online hour...
Time Card Calculator
Enter daily start, end and break times to total your weekly work hours. Optional hourly rate shows gross pay. Free online time ...
How It Works
Every tool on this site runs as a self-contained page in your browser. There is no backend server, no account and no upload: you type or paste a value, the page computes the result on your own device and displays it instantly.
Pick a tool from the grid below, make your selection or paste your data, and press the convert or calculate button. The result appears immediately with the values you need, ready to copy.
- All processing runs locally in your browser. Your data is not uploaded to any server.
- Timezones and daylight saving are handled by the browser date engine, so results stay accurate.
- No account, no sign-up, no tracking scripts - just the tool.
Frequently Asked Questions
Are all the time tools really free?
Yes. Every tool on time.olutil.com is free to use, runs entirely in your browser and needs no account or sign-up of any kind.
Do you upload or store the dates I enter?
No. All processing happens locally in your browser. Your dates, timestamps and timezones are never sent to any server.
What is a Unix timestamp?
A Unix timestamp counts the seconds since 1 January 1970 00:00:00 UTC. This tool converts between those numbers and normal dates.
Do these timezone tools keep daylight saving time correct?
Yes. Offsets are computed from your browser built-in timezone database, so daylight saving transitions are handled automatically.
Can I use these tools on my phone?
Absolutely. The whole site is responsive and works on any screen, and because every tool is self-contained you can keep it open as a reference.