How to use the date gap and streak finder
- Paste your dates, one per line or separated by commas, and choose the order of the parts: year-month-day, month-day-year or day-month-year.
- Optionally set an as-of date to decide whether the current streak is still running.
- Read the longest streak, the current streak, the number of days with no entry and the share of days covered.
- Use the gaps table to see each stretch of missing days, and download the streaks as a CSV.
Formula
sort the different dates and cut them into runs of consecutive days
streak length = last date of the run - first date + 1
gap length = next run start - previous run end - 1
share of days covered = different dates / (last date - first date + 1)
Only calendar days count. A repeated date counts once. The current streak is the run that ends on the latest date, or none if an as-of date is more than a day later.
Twelve days of a habit log
The list has the dates March 1, 2, 3, 5, 6, 9, 10, 11 and 12, with March 12 entered twice. There are 9 different dates over 12 calendar days, so 3 days have no entry: March 4, 7 and 8. The runs are March 1 to 3 (3 days), March 5 to 6 (2 days) and March 9 to 12 (4 days).
The longest streak is 4 days, starting March 9, and it is also the current streak because it ends on the latest date. The share of days with an entry is 75%. Entering 2026-03-14 as the as-of date would show a current streak of 0, because the latest date is more than a day before.
Dates in different formats
Dates are read in the order you choose, with a dash, slash or dot between the parts, and the year must have four digits. A date like 02/30/2026 is rejected because it does not exist, and so is a list in the wrong order, since 25/12/2026 cannot be a month-day-year date. The page names the first entry it could not read.
Uses and limits
Use it for habit logs, attendance, sign-in records or any list of event days. Weekends and holidays are not treated specially, so a log kept only on weekdays shows a gap every weekend. For comparing two ranges, use the Date Overlap Calculator; for counting days between two dates, the Days Between Dates Calculator; and to keep a daily habit, the Habit Tracker.
Assumptions and limits
- Dates have four-digit years between 1900 and 2200.
- Up to 5,000 dates are handled.
- Time of day and time zones are not considered.
- The page does not decide which gaps are acceptable.
Frequently asked questions
What counts as a streak?
A streak is a run of consecutive calendar days that all appear in your list. A single date on its own is a streak of one day.
How does the as-of date work?
If you leave it blank, the current streak is the run that ends on your latest date. If you set it, the run counts only when its last day is the as-of day or the day before.
Are repeated dates a problem?
No. Repeats are counted once and the page tells you how many were ignored.
Why was my date rejected?
The date may not exist, the year may have only two digits, or the order of the parts may not match the setting. Check the format and the order of the parts.