Random Date Generator

About the random date generator

1. Set Start Date and End Date. Both days are part of the period, and the start must not be later than the end.
2. Enter the Number of dates, from 1 to 100.
3. Choose an Output format. The menu shows an example of each pattern.
4. Press Pick a Random Date. A single date is shown on its own; several dates are listed one per line.

The starting values are a one-year window; change them to anything the date fields accept, from one day to several centuries. Dates are plain Gregorian calendar days, so there are no time zone shifts.

How a date is picked

The generator picks a random second between 00:00:00 on the start date and 23:59:59 on the end date, then writes that moment in the format you chose. Counting the seconds in the period gives the number of equally likely outcomes:

possible moments = (days from start to end, both included) × 86,400When the end date is later than the start date

Example: a period from 1 January to 31 December 2026 has 365 days, which is 365 × 86,400 = 31,536,000 seconds. March covers 31 of those days, so a single draw lands in March with probability 31 ÷ 365 = 8.49%. When the start and end dates are the same day, the generator has exactly one possible moment, midnight, so the answer is that day and any time shown reads 00:00:00.

Several dates in one run are all different moments. Two of them can still fall on the same calendar day when the time of day is not displayed, particularly in short periods; formats that include the time make the difference visible. Asking for several dates from a one-day period is refused, since only one moment exists.

Output formats

The last seven entries of the menu repeat the same patterns with the time of day added in 24-hour form, for example 2026-03-05 14:05:45. Days and months always carry a leading zero, and years are padded to four digits. The ISO 8601 pattern sorts correctly as plain text, which makes it the best choice when you will paste the dates into a spreadsheet.

How to get a random year or birthday

For a random day inside one year, set the period from 1 January to 31 December of that year. A leap year such as 2028 has 366 days, so every day has a chance of 1 ÷ 366, about 0.27%. To obtain just a year, choose a format that starts with the year, such as 2026 Mar 05, and read the first four digits. A random birthday is a date in a span of birth years: for people aged 18 to 65 today, set the start about 65 years back and the end 18 years back.

Browsers let you type years well outside the current century, so historical ranges work too. The calendar used is the modern Gregorian one extended backwards, which can differ from the dates written in historical records.

Applications of a random date picker

• Test data for forms, databases and calendars, using the time-stamped formats.
• Trivia, history lessons or writing prompts based on a random day.
• Sampling days for audits or spot checks, where a fair random draw is easy to explain.

To count the days between two dates or find which weekday a date falls on, try the days between dates calculator and the weekday calculator. Other draws: the random name picker and the random team generator.