Should I use Seconds or Milliseconds output?
It depends on your backend stack. PHP, Python, Ruby, and standard Unix APIs usually expect 10-digit Seconds. Javascript (`Date.now()`) and Java generally expect 13-digit Milliseconds.
Date to Timestamp Converter is a precision developer tool that transforms human-readable Calendar dates and times (e.g., "October 10, 2025 15:30") into machine-readable integer Unix Epoch timestamps. Ideal for software engineers writing database migration scripts, mocking API responses, or generating exact expiration times for security tokens and cached objects without writing ad-hoc scripts.
Computers do not natively understand "Months" or "Days" because they are irregular (leap years, 28 vs 31 days). To solve this, POSIX systems track time purely as a running tally of seconds elapsed since January 1, 1970 00:00:00 UTC (The Epoch). This tool simply determines the total duration between 1970 and your selected date, outputting the absolute integer.
It depends on your backend stack. PHP, Python, Ruby, and standard Unix APIs usually expect 10-digit Seconds. Javascript (`Date.now()`) and Java generally expect 13-digit Milliseconds.
Yes! The Unix Epoch is globally absolute (always UTC). However, when you input "12 PM", it must know whether you mean 12 PM in London or 12 PM in Tokyo. You can specify the input timezone via the tool settings.
For systems using 32-bit signed integers, timestamps cannot exceed 2,147,483,647 (which lands in Jan 2038). If you generate dates past 2038, ensure your database schema parses them using 64-bit integers (BIGINT).
Yes, dates prior to January 1, 1970 generate a negative integer timestamp. However, some legacy systems crash when attempting to process negative timestamps.
Yes, the calculation is performed locally using the browser's JavaScript engine without any server dependencies.
Yes, it is totally free to use.
Tool workspace
Free Date to Unix Timestamp converter online — instantly transform calendar dates and times into Epoch integer format (seconds or milliseconds) for databases and APIs. No login.
Input
January 1, 2024 at 12:00:00 AM UTC
Output
1704067200 (Seconds) / 1704067200000 (Milliseconds)