Days Since Date Calculator – Count Days Between Dates
Quickly check how many days have passed
What this tool does. The Days Since Date Calculator shows exactly how many days have passed between two calendar dates, usually from a past date up to today. It also gives you the same gap as full weeks plus extra days and a simple months-and-days style breakdown, all in one clear line so it’s easy to read, screenshot, or paste.
How it works. Choose a Start date (the date you want to count from) and an End date. The end date defaults to today, so you can quickly answer questions like “How many days since I started this project?” or “How many days since this invoice date?”. The calculator validates that both dates are real calendar dates (including leap years) and only accepts end dates that are on or after the start date, which matches the idea of “days since”.
What the result shows. After you hit Calculate days, the bold line shows the total number of days between your two dates. Underneath, the facts strip converts that same gap into weeks plus extra days, the total weeks only, and a months-and-days style breakdown, along with labels for your chosen start and end dates. It’s designed to match the style of your other time & date tools: one compact card, one main answer, and a horizontal row of supporting numbers.
Typical uses. Use this calculator to track how many days have passed since a habit change, a milestone, a launch date, a due date, an anniversary, or any personal or historical event. It also works well for KPI dashboards, streak tracking, contract or warranty periods, and content planning around “X days since…” headlines.
Step-by-step. Set the Start date, leave the End date as today if you’re checking “days since today”, or change it if you need to stop the count at another date. Click Calculate days or press Enter while focused on any dropdown to run the calculation. You can then adjust either date and recalculate as many times as you like.
How it fits with your other tools. For a weekly view, switch to the Weeks Between Dates Calculator. To find out how old you were on a certain date, try the How Old Was I Calculator, or for your full current age, use the Age Calculator. All of these tools share the same layout and language so users instantly feel familiar.
Accuracy & privacy. All calculations run in your browser using real calendar rules, including leap years and different month lengths. No dates or results are sent to any server, stored, or logged. As long as your device’s time and date settings are correct, the Days Since Date Calculator provides an accurate and private way to measure time passed.
FAQs
Can the end date be in the future?
Yes. You can choose any end date on or after the start date, including future dates, to see how many days will have passed by that point.
What if I pick an end date before the start date?
You’ll see an error message. For a “days since” style calculation, the end date has to be the same as or later than the start date.
Does it account for leap years?
Yes. All calculations are based on actual calendar dates, so leap days and different month lengths are handled correctly.
Can I copy the result?
Use the “Copy summary” button under the result to grab a plain-text description of the gap for emails, notes, and reports.