Enter a start date
Start date is a single calendar date from 1 January 1900 through 31 December 2100. Show 75 dates fills the result. Print date list sends the list to your browser’s print dialog (A4 or Letter, portrait). Reset example restores 3 September 2026 and the labelled example results.
Day 1 is the date you entered. Day n is that date plus (n − 1) calendar days. Day 75 is therefore start + 74 days. Both ends are inside the 75. Day 75 may fall in 2101 when Day 1 is late in 2100.
The example:
| Date | Weekday | |
|---|---|---|
| Day 1 | 3 September 2026 | Thursday |
| Day 75 | 16 November 2026 | Monday |
Independent check: from 3 September 2026 to 16 November 2026 there are 74 whole days, so the inclusive length is 75. The Tallyrow app uses the same inclusive rule for a 75-day run. A second check: start 23 August 2026 ends on 5 November 2026.
JavaScript is required to compute a date you type. Without it, the example table on this page remains visible and the controls stay inactive.
Reloading or leaving this page clears the date you typed. Print the list if you want a copy that remains.
Read the checkpoints
These are not rest days and not scoring gates. They are checkpoints at Day 1, 15, 30, 45, 60 and 75.
For start 3 September 2026:
| Day | Offset | Date | Weekday |
|---|---|---|---|
| 1 | 0 | 2026-09-03 | Thursday |
| 15 | 14 | 2026-09-17 | Thursday |
| 30 | 29 | 2026-10-02 | Friday |
| 45 | 44 | 2026-10-17 | Saturday |
| 60 | 59 | 2026-11-01 | Sunday |
| 75 | 74 | 2026-11-16 | Monday |
Day 30 in that example is 2 October, not 3 October: September has 30 days, so 3 September plus 29 days lands on 2 October. If a result looks “a day off,” check whether you counted 75 additions instead of 74, or started the count on Day 0.
The list under the result names every day from 1 to 75 with ISO dates (YYYY-MM-DD) and English weekdays. Print it if you want the list beside a paper calendar.
Leap days, new years, and clock changes
The count follows the Gregorian civil calendar.
Leap day. 2028 is a leap year. If Day 1 is 1 February 2028, Day 29 is 29 February 2028 and Day 30 is 1 March 2028. Day 75 is 15 April 2028. If Day 1 is 29 February 2028, Day 2 is 1 March 2028 and Day 75 is 13 May 2028.
Non-leap February. 2027 is not a leap year. 29 February 2027 is not a date; the calculator rejects it. If Day 1 is 28 February 2027, Day 2 is 1 March 2027.
Year boundary. If Day 1 is 1 December 2026, Day 75 is 13 February 2027. The year number changing does not add or drop a day.
Clock changes. Where clocks change, a day may have 23 or 25 hours. That does not add a calendar day to this list. 7 March to 10 March is still three calendar days. This calculator never takes a time of day, so a time zone cannot shift Day 75.
Travelling across a date line can change which civil date your phone shows as “today.” This page does not compensate for travel. Pick the civil date you want to call Day 1 in the place you will keep the record.
Invalid values
The calculator needs one real calendar date in range. Editing the field hides the previous list until the new date is valid.
| Input | What happens |
|---|---|
| Empty | “Enter a start date.” No list. |
| 30 February 2026 | “That date is not on the calendar.” The typed value stays. |
| 31 April 2026 | Same rejection. April has 30 days. |
| 29 February 2027 | Same rejection. 2027 is not a leap year. |
| 1899-12-31, 2101-01-01, 0000, 0099, 9999 | “Enter a start date from 1 January 1900 to 31 December 2100.” |
| Letters or a partial date | “Enter a date as YYYY-MM-DD.” |
| 1900-01-01 | Accepted. Day 75 is 16 March 1900. |
| 2100-12-31 | Accepted. Day 75 is 15 March 2101. |
Impossible calendar days are not rolled into the next month.
Print the 75 dates
Print date list prints the title, the start and last days, the six checkpoints, and every Day 1–75 line. The surrounding article does not print. The sheet uses two columns so the 75 lines fit one portrait A4 or Letter page.
What this does not count
This is a date list for a 75-day record you define. Skipping a day does not move Day 75 unless you choose a new Day 1. The list does not apply the app’s missed-day restart.
This website calculator is free. The Tallyrow app is a separate product and requires paid access. See the product page for current availability.
To print a two-page sheet with tick boxes and a handwriting notes column, use the 75-day challenge tracker. Website analytics are described in the privacy policy.