Thirty days: the one-month planning window
Thirty days is the number many people reach for when they mean "about a month". The page adds exactly thirty days to the date on your device and prints the result with its weekday and ISO week number. It also gives the date thirty days earlier, which is useful for looking back over the last month.
Note that thirty days is not the same as one calendar month. Starting on 12 March, thirty days ends on 11 April, a day before the same date next month. Months with 31 days make the gap larger, and February makes it smaller. If you want the same date next month, use the date calculator or the 6 months page for how that works.
Typical uses are a 30-day challenge, a month-long project cycle, a trial that is described in days, or a reminder to revisit a decision. A habit tracker with thirty boxes needs a finish line, and this gives you the exact date to write on it.
The weekday shifts by two from today, since thirty days is four weeks and two days. Start on a Friday and you finish on a Sunday, which matters if a deadline should avoid a weekend.
Worked examples
Questions about this tool
Is 30 days the same as one month?
Not always. A month can be 28 to 31 days, so thirty days can end a day or two before or after the same date next month.
Why does the weekday change?
Thirty is not a multiple of seven, so the answer falls two weekdays later than today.
How do I count a 30-day challenge that starts today?
If day 1 is today, the last day is 29 days later. If you start tomorrow, use the 30 day result as the last day.