Date & Time Calculators
Free calculators for time duration, date arithmetic, countdowns, work-day planning, and time zone conversion. Each tool handles edge cases like overnight spans, AM/PM crossovers, and holiday exclusions that manual calculation gets wrong.
Featured Calculators
- time duration calculator for hours between two times
Calculate the exact hours and minutes between any two times. Handles same-day and overnight spans automatically.
- date difference calculator between two dates
Find the exact number of days, weeks, and months between any two calendar dates.
- business work days calculator excluding holidays
Count business days between two dates, optionally excluding US federal holidays.
- countdown calculator — days remaining until a target date
Calculate how many days, hours, and minutes remain until any upcoming event or deadline.
- add or subtract days from a date calculator
Find a future or past date by adding or subtracting a number of days from a starting date.
- time zone converter across multiple cities
Convert a time across multiple time zones simultaneously for scheduling across regions.
All Date & Time Tools
- Age Calculator
Calculate exact age from birth date to a reference date.
- Weekday Finder
Find the day of week for any calendar date.
- Unix Timestamp Calculator
Convert a date-time to Unix epoch seconds.
- Leap Year Calculator
Check whether a year is a leap year.
- Week Number Calculator
Find ISO week number for a date.
- Julian Date Calculator
Convert Gregorian date to Julian Day Number.
- Meeting Time Planner
Find the best times to call or meet across two different time zones.