Free Online Tool

Date Calculator

Calculate days between dates or add/subtract business days and calendar days from a given date.

Interactive Date Calculator

Other

Start Date

Days to Add / Subtract

Tuesday, September 1, 2026

Difference in milliseconds converted into calendar days, weeks, and months.

Our mathematical algorithms adhere to standard scientific and financial guidelines to deliver maximum accuracy.

You can specify calendar days or exclude weekends depending on calculation mode.

Calculate exact age in years, months, days, hours, and minutes from date of birth.

Add, subtract, convert, and calculate elapsed time intervals in hours, minutes, and seconds.

Calculate total work hours, weekly timecard totals, and break time deductions for payroll.

Calculate high school or college Grade Point Average (GPA) on weighted or unweighted 4.0 scales.

Determine what score you need on your final exam to achieve your desired target course grade.

Calculate concrete volume in cubic yards or meters and estimated bag counts for slabs, footings, and steps.