Date and time calculators
Work with calendar dates and clock times without turning months into averages or hiding how overnight intervals are handled.
Calculators in this section
Compare dates or add and subtract calendar units.
Business daysCount weekdays and optional US federal holidays.
Time durationFind hours and minutes between two clock times.
Time cardTotal weekly shifts and subtract unpaid breaks.
Age calculatorFind calendar age on today or another date.
Military timeConvert between 12-hour and 24-hour clock times.
Decimal timeConvert hours and minutes to decimal hours and back.
Calendar units stay calendar units
Months are added as months, leap days stay visible, and business-day counts state exactly which endpoints and holidays are included.
Arithmetic, not policy
The time-card and business-day tools calculate the values you enter. They do not decide payroll eligibility, legal deadlines or an organization’s holiday policy.
Frequently asked questions
Which time zone do date calculations use?
Date-only calculations use calendar dates rather than a clock or time zone. Clock-duration tools use the times exactly as entered.
Are US federal holidays always excluded?
No. The business-day calculator excludes them only when you enable that option.