Free Date & Time Tools
Calculate the difference between dates, add or subtract days, find week numbers, check leap years, and more with our free date and time tools.
Date Difference Calculator
How many days until your deadline? How many months since you started a project? Enter two dates and instantly see the difference broken down into days, weeks, months, and years — no mental math required.
Use tool →Add Days to Date
Need to know the date 90 days from now? Enter a starting date and the number of days to add, and the tool returns the exact future date. Handy for contract deadlines, delivery estimates, and countdown planning.
Use tool →Subtract Days from Date
When did a 30-day warranty start? What was the date 14 days before launch? Enter a date and the number of days to subtract, and the tool reveals the earlier date in an instant.
Use tool →Add Months to Date
Calculating subscription renewals, lease expirations, or quarterly milestones? Enter a date and the number of months to add, and the tool handles varying month lengths — including the tricky ones like February.
Use tool →Add Years to Date
Planning for a five-year warranty expiry or a golden wedding anniversary? Enter a date and the number of years to add. The tool accounts for leap years so you always get the correct calendar date.
Use tool →Week Number Calculator
What week of the year is it? Enter any date and get its ISO 8601 week number instantly. Whether you're scheduling sprints, tracking payroll periods, or filing weekly reports, this tool keeps you aligned.
Use tool →Day of Year Calculator
January 1 is day 1, December 31 is day 365 (or 366). Enter any date and instantly see its ordinal day number within the year — handy for Julian date conversions, scientific records, and agricultural planning.
Use tool →Day of Week Calculator
Was your birthday a Tuesday? Will Christmas fall on a weekend this year? Enter any date — from centuries ago to decades ahead — and instantly see the day of the week. Never second-guess the calendar again.
Use tool →Leap Year Checker
Leap years add an extra day to February, but the rules are trickier than you think (divisible by 4, except centuries, unless divisible by 400). Skip the mental gymnastics — type a year and get a definitive answer.
Use tool →Days in Month Calculator
Does September have 30 or 31 days? What about February 2028? Enter a month and year to get the exact day count — no knuckle-counting tricks needed.
Use tool →Business Days Calculator
Shipping says 10 business days — but when exactly is that? Enter a start date and the number of business days (or two dates) and the calculator skips Saturdays and Sundays to give you the precise result.
Use tool →Days Until Calculator
Pick any future date and see exactly how many days remain from today. Perfect for building anticipation for holidays, tracking days until a product launch, or staying on top of an important deadline.
Use tool →Days Since Calculator
How long have you been at your job? How many days since you quit smoking? Enter a past date and see the exact number of days that have elapsed — great for tracking personal milestones, habit streaks, and project durations.
Use tool →Learn More
Read our comprehensive guide to get the most out of these tools.
Read the Date & Time Tools Guide →