About Day Since

Why Day Since exists

Counting days sounds like a solved problem, but a lot of day counters get the details wrong. Some are a day off around daylight saving changes. Some show yesterday’s number because the page was cached. Others bury a simple answer under pop-ups. Day Since was built to give the right number quickly, on any phone, without asking you for anything.

How the math is checked

Every count on the site comes from one small calculator that runs in your browser. Dates are turned into whole day numbers before they are compared, so time zones and clock changes cannot shift the result. Leap years follow the Gregorian rule: every fourth year, except century years that are not divisible by 400.

Before any change goes live, the calculator is run against a list of known answers. It includes leap-day spans such as February 28 to March 1, 2024 (2 days), daylight-saving weekends, month-end edge cases, business-day counts, ISO week numbers, and holiday rules such as US Thanksgiving on the fourth Thursday of November (November 26, 2026) and Easter. If a result ever looks wrong to you, please tell us the dates you used and we will check it against that list.

What we do and do not do

• Your dates are calculated on your own device. They are not saved or sent to us.
• Live counts are never stored in the page itself, so they cannot go stale.
• No accounts, no sign-up and no fake reviews, ratings or user numbers.
• Health-related pages, such as the quit-smoking and sobriety counters, share general, well-established information only and point you to a doctor or helpline for advice.

Where to start

The day since calculator on the homepage counts the days since, until or between any dates. Popular pages include the Christmas countdown, the days between dates calculator and what day of the year it is.

Contact

Questions, corrections or ideas for a new counter are welcome. Email [email protected] or use the contact page.