Date Difference Calculator

Use this calculator whenever you need the exact elapsed time between two date-times down to the second, and don't need to worry about which date comes first—unlike the Hours Between Dates Calculator, this one accepts either order.

Each date and time is combined as a UTC instant. The result breaks the absolute difference into non-overlapping days, hours, minutes, and seconds (for example, 1 day 3 hours is shown as 1 day and 3 hours, not 27 hours).

If the end is before the start, the calculator still shows the length of the gap. For calendar days only (ignoring time of day), use Days Between Dates. To count down to a future moment, try the Countdown Timer.

Start: 9:00:00 AM UTC on a Monday. End: 12:00:00 PM UTC the following Tuesday.

Raw span: 27 hours.

Breakdown: 1 day, 3 hours, 0 minutes, 0 seconds—the non-overlapping form of 27 hours.

If the start and end were swapped (end entered as the earlier timestamp), the result would show the same 1 day, 3 hours breakdown, since the calculator measures the absolute gap regardless of order.

The Business Days vs Calendar Days Guide explains when weekends and holidays count and which day type applies to deadlines, invoices, and contracts.

The How Business Days Are Calculated Guide and Business Days Between Dates Guide cover the counting rules behind every business-day tool on this site.

The Business Days Calculator and Working Days Calculator count weekdays between two known dates, excluding weekends and optional US federal holidays.

The Add Business Days To Date, Subtract Business Days From Date, and Business Day Offset calculators move a single date forward or backward by a business-day count.

The Business Days Until Date Calculator counts business days remaining from today or a custom date to a target deadline.

The Days Between Dates Calculator counts every calendar day between two dates, including weekends—use it instead of the business-day tools when weekends should count.

The Date Range Calculator and Date Duration Calculator break a range into calendar-day totals or a years/months/days breakdown, with inclusive or exclusive boundary options.

The Add or Subtract Days Calculator shifts a single date forward or backward by days, weeks, or months.

The Age Calculator applies the same calendar breakdown used by Date Duration to a birth date, expressed as years, months, and days.

The Hours Between Dates and Date Difference calculators measure elapsed time between two date-times down to hours, minutes, and seconds.

The Date Format Converter, Unix Timestamp Converter, and Timezone Converter handle format and zone conversion for a single instant rather than a span between two dates.