Date & Time Utilities
34 tools available. All calculations and file processing stay 100% private in your browser.
Convert 10
- 12-Hour to 24-Hour Time Converter (AM/PM)Convert between 12-hour AM/PM clock notation and 24-hour military time formats bidirectionally.
- Add Days to Date Calculator (+N Days)Calculate future calendar dates by adding N days to any reference date, with day of week and ISO week details.
- Add Months to Date Calculator (+N Months)Add calendar months to any date, with automatic end-of-month clamping for shorter months and leap years.
- Add Weeks to Date Calculator (+N Weeks)Add a specified number of 7-day weeks to any reference date to find the target future date.
- Add Years to Date Calculator (+N Years)Add full calendar years to any date, with leap year February 29th clamping to February 28th.
- Date to Unix Timestamp ConverterConvert human-readable date and time strings into 10-digit second and 13-digit millisecond Unix epoch timestamps.
Create 2
- Calendar Date List Generator (Custom Date Range)Generate complete sequential lists of dates within a range, with options to include all days, weekdays only, or weekends only.
- Find Dates by Weekday Generator (e.g. All Fridays)Find and list all specific days of the week (e.g. all Mondays or all Fridays) within any chosen date range.
Organize & Edit 2
- Date Format Converter (ISO, Slash, Dot & Regional)Convert date strings between standard formats including YYYY-MM-DD, YYYY/MM/DD, DD/MM/YYYY, MM/DD/YYYY, and YYYYMMDD.
- ISO 8601 Date & Time FormatterFormat arbitrary date and time inputs into strict standard ISO 8601 representations (date-only, local combined, UTC Z).
Calculate & Analyze 18
- Add Business Days Calculator (Skip Weekends)Add N working business days to a starting date, automatically skipping weekend Saturdays and Sundays.
- Business Days Calculator (Excluding Weekends)Calculate working business days (Monday through Friday) between two dates, automatically excluding Saturdays and Sundays.
- D-Day & Countdown CalculatorCalculate remaining days until a future target event (D-Day countdown) or elapsed days since a past anniversary.
- Day of the Week CalculatorDetermine the exact day of the week (Monday through Sunday) for any historical or future calendar date.
- Day of the Year Calculator (Julian Ordinal Day)Calculate the ordinal day number of the year (1 through 365/366) and remaining days in the year.
- Days Between Dates CalculatorCalculate the exact number of days between two calendar dates, with inclusive and exclusive boundary counts.
Inspect & Extract 2
- Leap Year Checker (Gregorian Rule)Check whether any year is a leap year according to official Gregorian calendar rules (divisible by 4, not 100 unless 400).
- Timezone Converter (World Time Zone)Convert dates and times across major global timezones with full daylight saving time (DST) offset adjustment.