# Add or Subtract Days Add or subtract years, months, weeks and days from a date — and see the resulting date and weekday. Runs entirely in your browser. 30 days later · 2026-08-25 ### How it works Years and months are applied first with calendar arithmetic (so “+1 month” from 31 Jan lands in early March, since February has no 31st), then whole weeks and days are added or subtracted. The result shows the final date, its weekday, and the net number of days from your start date — all computed on your device. --- *Source: [ocxly.com/date-add-subtract.html](https://ocxly.com/date-add-subtract.html) — OCXLY, free 100% client-side privacy-first tools. Free date calculator. Add or subtract years, months, weeks and days from a date and see the resulting date and weekday, entirely in your browser.*