Date & Time · 13 calculators
Date & Time Calculators
Work out ages, durations, deadlines, and timesheets in seconds — from "how many days until" to hours worked and business days.
Dates
Age Calculator
Your exact age in years, months, and days.
Date Difference
Days, weeks, and months between two dates.
Add to Date
Add or subtract days from any date.
Business Days Calculator
Working days between two dates.
Day of the Week
Which weekday any date falls on.
Week Number
The ISO week number for a date.
Time
Countdown & more
About our date & time calculators
Dates and times are fiddly to count by hand, especially across months and leap years. These tools handle the calendar maths for you, so a deadline, an age, or a timesheet is always exact.
Every tool here is free, works instantly in your browser, and never stores the numbers you enter. They give reliable results for everyday use — treat anything high-stakes as a starting point and double-check with a professional.
Frequently asked questions
Yes. Every date & time calculator on OnlineCalculators.com is completely free, with no sign-up, account, or app required.