Date & Time calculators

Date Calculator

Find the number of days between two dates, add or subtract days from a date, or count down to New Year's Day, Halloween, Thanksgiving, and Christmas.

World Clock & Time Zone Converter

See the current time in dozens of cities worldwide, or convert a specific date and time from one time zone to another, including the day-of-week shift and daylight-saving status.

Time Duration Calculator

Find the elapsed time between two clock times, add or subtract hours and minutes from a time, or calculate the duration between two full dates and times, with automatic overnight rollover.

Age Difference Calculator

Find the exact age gap between two people from their birth dates, in years/months/days and as a percentage of the older person's age, plus the "half your age plus seven" reference rule.