Timestamp
Timestamp Converter
Convert Unix Timestamp to Date and vice versa.
What
Timestamp Converter definition
A Unix timestamp is the number of seconds or milliseconds since 1970-01-01 00:00:00 UTC; this tool converts between timestamps and human-readable dates.
Cases
Use Cases
1
Convert epoch values from logs into readable dates
2
Generate current timestamps for APIs or tests
3
Check whether a value is seconds or milliseconds
How To
How to Convert Unix Timestamps
A step-by-step guide to converting between timestamps and dates.
1
Choose direction
Select Timestamp→Date or Date→Timestamp tab.
2
Enter value
Type the timestamp or pick a date/time.
3
View results
See the conversion in ISO, UTC, RFC and other formats, then copy.
Knowledge
Understanding Unix Timestamps
What is Unix Time?
Unix time (POSIX time) counts seconds since January 1, 1970, 00:00:00 UTC—the 'Unix epoch'. It provides a universal, timezone-independent way to represent moments in time.
Seconds vs Milliseconds
Traditional Unix timestamps use seconds. JavaScript's Date.now() uses milliseconds. Many APIs accept both. Always verify the expected unit—a 10-digit number is seconds; 13 digits is milliseconds.
Year 2038 Problem
32-bit signed integers overflow on January 19, 2038. Systems using 32-bit timestamps will fail. Most modern systems use 64-bit timestamps, which won't overflow for billions of years.
ISO 8601 Format
ISO 8601 (e.g., 2024-01-15T14:30:00Z) is the international standard for date/time strings. The 'Z' suffix indicates UTC. Offset notation (+05:30) indicates timezone difference from UTC.
Time Zones and DST
Always store timestamps in UTC to avoid timezone and daylight saving time issues. Convert to local time only for display. Be aware that timezone rules change—use updated timezone databases.
FAQ
Timestamp converter FAQ
What is a Unix timestamp?
Seconds or milliseconds since 1970-01-01 00:00:00 UTC; used for logs, cache expiry, and scheduling.
When should I use ISO 8601 or RFC 3339?
Use ISO 8601 / RFC 3339 strings (e.g., 2025-12-07T12:34:56Z) for API or database responses where a clear timezone matters.
What is RFC 7231 time format for?
RFC 7231 defines the HTTP-date format like "Sun, 07 Dec 2025 12:34:56 GMT" for headers such as Date and Expires.
Should I store timestamps in seconds or milliseconds?
Unix timestamps default to seconds, while JavaScript Date.now() uses milliseconds. Convert to the unit your API expects to avoid double-scaling.
How do I avoid timezone mistakes when converting?
Always clarify whether an input is UTC or local time. Convert local times to UTC before storing timestamps to prevent daylight-saving shifts.
Why did Unix time start in 1970?
The Unix epoch began at 1970-01-01 00:00:00 UTC for simplicity on early Unix systems and has remained the shared reference for cross-platform timekeeping.
How common are Unix timestamps today?
They remain one of the most used time formats across databases, logs, SDKs, and REST or gRPC APIs because they are language-agnostic and compact.
Where are timestamps used most often?
Event logging, cache expiration, scheduling, analytics pipelines, and signature generation rely on Unix timestamps for consistent ordering.
Any best practices for maintaining timestamp data?
Store UTC, label units (seconds vs. milliseconds), and avoid storing human-formatted strings when you need precise comparisons or arithmetic.