Random Time Generator: Create Bulk Random Times in Multiple Formats
Random times are needed for test data, schedule simulations, appointment generators, and any application that handles time-based data. Our generator produces uniformly distributed random times across the full 24-hour day in four formats.
Generate up to 500 times at once and copy them for use in spreadsheets, SQL inserts, JSON data, or any other time-based dataset.
Time generation algorithm:
Time Format Reference
12-Hour (HH:MM:SS AM/PM): 03:45:22 PM - standard in US/UK consumer contexts
24-Hour (HH:MM:SS): 15:45:22 - international standard, used in most APIs and databases
Timestamp (HH:MM:SS.mmm): 15:45:22.547 - for sub-second precision in event logs
Seconds Since Midnight (integer): 56722 - timezone-independent for arithmetic
All formats represent times uniformly distributed across the full 24-hour day.
Use in SQL and Databases
Generated times can be used directly in SQL:
INSERT INTO events (time) VALUES ('15:45:22');
-- or with date prefix:
INSERT INTO events (created_at) VALUES ('2024-03-15 15:45:22');
For MySQL: TIME type accepts HH:MM:SS format
For PostgreSQL: TIME type or INTERVAL
For SQLite: store as text in ISO 8601 format
Practical Examples
Event log test data
- 1.Format: Timestamp (with ms)
- 2.Count: 50-100 entries
- 3.Use: Paste into event log CSV for testing parsers
Schedule simulation
- 1.Format: 24-Hour or 12-Hour
- 2.Count: Match appointment slots needed
- 3.Sort: Copy to spreadsheet and sort A-Z
Frequently Asked Questions
What time formats does the generator support?
The generator supports: 12-Hour format (e.g. 03:45:22 PM), 24-Hour format (e.g. 15:45:22), Timestamp with milliseconds (e.g. 15:45:22.547), and Seconds Since Midnight (e.g. 56722 = 15:45:22). These cover the most common time representations in applications and data work.
What are seconds since midnight?
Seconds since midnight (also called seconds of day) represents a time as the total number of seconds elapsed since 00:00:00. It ranges from 0 (midnight) to 86399 (23:59:59). This format is timezone-independent and convenient for time arithmetic in programming.
What is the timestamp format with milliseconds?
The timestamp format adds a 3-digit millisecond component: HH:MM:SS.mmm (e.g. 14:30:22.547). This is useful for generating test data for event logs, performance metrics, and any system where sub-second precision is needed.
Are the times uniformly distributed?
Yes. The generator produces hours (0-23), minutes (0-59), and seconds (0-59) each with equal probability using Math.random(). Every possible time within a day is equally likely to be selected.
How many times can I generate at once?
You can generate up to 500 times at once. This is suitable for populating test datasets, generating sample schedule data, or creating realistic event timestamps for testing.
Can I generate times without seconds?
Yes. For 12-Hour and 24-Hour formats, you can uncheck the Include seconds checkbox to generate times in HH:MM format only. The Timestamp and Seconds formats always include seconds as they are their defining characteristic.
What are good use cases for random times?
Test data generation (event timestamps, scheduled times), unit testing of time parsing functions, generating sample appointment schedules, creating realistic time entries for demo data, and teaching probability and statistics.
How do I convert seconds since midnight back to HH:MM:SS?
Divide by 3600 for hours (floor), take remainder divide by 60 for minutes (floor), remainder is seconds. Example: 56722 seconds: 56722 / 3600 = 15 hours, 56722 mod 3600 = 1522, 1522 / 60 = 25 minutes, 1522 mod 60 = 22 seconds = 15:25:22.