Date and time calculators
22 calculators
Date and time calculators convert clock formats, compute age, tick a live age from a date of birth, and find spans between calendar dates using the rules described on each page.
Calendar math follows the tool’s stated convention (for example 24-hour mapping of AM/PM). Time-zone and leap-second edge cases are called out only where the How it works text mentions them. Date tools are free — no account to get started.
Clocks calculators
12/24-hour time and timezone offset.
Calendar spans calculators
Days, weeks, months, and hours from a reference date.
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Date Calculator
Add or subtract days from a starting date.
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Days Ago Calculator
Find the calendar date N days before today.
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Days From Today Calculator
Find the calendar date N days after today.
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Days Until Calculator
Count whole days from today until a target date.
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Hours Ago Calculator
Find the date/time N hours before now.
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Hours Calculator
Compute the number of hours between two date/times.
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Hours From Now Calculator
Find the date/time N hours from now.
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Minutes Ago Calculator
Find the date/time N minutes before now.
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Minutes From Now Calculator
Find the date/time N minutes from now.
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Months Ago Calculator
Find the calendar date N months before today.
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Months From Now Calculator
Find the calendar date N months after today.
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Weeks Ago Calculator
Find the calendar date N weeks before today.
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Weeks From Now Calculator
Find the calendar date N weeks after today.
Age and duration calculators
Age, live ticking age, work hours, and how-long-until helpers.
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Age Calculator
Calculate age in years, months, and days from a birth date.
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Age On Date Calculator
Exact age in years, months, and days on a target date.
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Business Days Add Calculator
Add N business days (Mon–Fri) to a start date.
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How Long Until Calculator
Show days, hours, and minutes remaining until a target.
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Live Age Calculator
Watch age tick in years, months, days, hours, minutes, and seconds from a date of birth.
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Work Hours Calculator
Hours worked between start/end times with break.