- Instant answersResults update as you type.
- Private by designRuns in your browser. Nothing is sent.
- Share, print or citeCopy a link with your numbers.
Upcoming
- Days until HalloweenSaturday, October 31, 2026
- Days until Veterans DayWednesday, November 11, 2026
- Days until Thanksgiving (US)Thursday, November 26, 2026
- Days until Black FridayFriday, November 27, 2026
- Days until Cyber MondayMonday, November 30, 2026
- Days until Christmas EveThursday, December 24, 2026
Tools
- Days until any dateCountdown in days and weeks
- Date difference calculatorDays, weeks and months between two dates
- Add or subtract daysDate N days from any date
- Age calculatorExact age and next birthday
- Day of the week finderWhat day was any date
- Business days calculatorWeekdays between dates
- Time card calculatorHours worked with breaks
- Week numberISO week of any date
- Days left in the yearYear progress
- Half birthday calculator6 months after your birthday
- Sleep calculatorBedtimes by sleep cycles
- Dog age calculatorDog years to human years
- Cat age calculatorCat years to human years
- Overtime calculatorTime-and-a-half pay
- Unix timestamp converterEpoch time ↔ date
- Military time converter24-hour ↔ 12-hour
- Electricity cost calculatorCost to run any device
- Hourly to salary calculatorHourly ↔ annual pay
Popular quick answers
What DateRuler does
DateRuler answers everyday date, time and small-money questions with exact calendar arithmetic: how many days until a date, how old someone is to the day, which date falls 90 business days from now, what an appliance costs to run, or how an hourly rate converts to a salary. Every tool runs in your browser, updates as you type, and shows how the answer was worked out.
How the results are checked
Date maths uses the Gregorian calendar in UTC so daylight-saving changes never shift a count. Federal holidays follow 5 U.S.C. 6103 and the observed-day rules from the U.S. Office of Personnel Management. Pay tools follow the federal overtime rule in the Fair Labor Standards Act, and electricity costs use the U.S. Energy Information Administration's average residential prices by state. Each tool has its own automated tests, which run before every update. Read the editorial policy for how pages are reviewed and corrected.
Popular starting points
- Age calculator gives exact years, months and days, plus your next birthday.
- Add or subtract days works forward or back from any date, with business days.
- Business days calculator skips weekends and the 11 federal holidays.
- Electricity cost calculator uses your state's average rate.
- Hourly to salary converts pay by week, month and year.