SO SimonOS
Time & Date Live tool

Date Difference Calculator

Calculate days, hours, and calendar parts between two YYYY-MM-DD dates with optional inclusive counting.

Tool Flow

01 Input 02 Process 03 Output

Tool Guide

About the Date Difference Calculator

Use the Date Difference Calculator to count days, hours, and calendar parts between two dates. It supports normal exclusive date spans and inclusive end-date counting for planning, schedules, deadlines, and trip lengths.

Common uses

  • Count days until a deadline or launch date.
  • Calculate trip, project, or billing period lengths.
  • Compare same-day ranges with inclusive counting.
  • Break a date span into years, months, and days.

Browser workflow

  1. 01 Choose the start and end dates.
  2. 02 Toggle inclusive end-date counting if your workflow needs it.
  3. 03 Read the total days, hours, and calendar breakdown.