Epoch Time Converter
Convert Unix epoch timestamps to human-readable dates and back. Works with seconds or milliseconds, auto-detects common formats, and keeps outputs ready to copy for logs, APIs, and scripts.
Epoch → Date/Time
Local
Dec 16, 2025, 9:45:20 PM UTC
UTC
Dec 16, 2025, 9:45:20 PM UTC
ISO 8601
2025-12-16T21:45:20.000Z
Date/Time → Epoch
Epoch seconds
1765921520
Epoch milliseconds
1765921520000
Table of Contents
What is epoch time?
Epoch time (also called Unix time) counts the milliseconds or seconds since January 1, 1970 UTC. It is used by APIs, databases, and log files because it is time zone agnostic and easy to compare.
This converter lets you turn raw epoch numbers into readable timestamps—or take a date/time and produce exact epoch values—without worrying about formatting or units.
How this converter helps
1) Paste any epoch
Seconds or milliseconds are detected automatically. You will see local, UTC, and ISO outputs instantly.
2) Build timestamps
Select local time or UTC, set the date and time, and get both epoch seconds and milliseconds.
3) Copy anywhere
Use the copy buttons to move clean values into logs, API calls, or scripts.
Tips for clean conversions
Know your unit
APIs may expect seconds, while databases often store milliseconds.
Anchor to UTC for APIs
UTC avoids daylight saving surprises in server-side code.
Keep ISO strings
ISO 8601 outputs are easy to compare and log.
Validate inputs
Large 13-digit values are milliseconds; 10-digit values are seconds.
Examples and everyday use cases
Incident timelines
Drop alert epochs to line up events across services. Copy ISO strings into post-incident docs so everyone references the exact same moment.
API scheduling
Generate UTC epochs for delayed jobs or webhooks. Keep both seconds and milliseconds handy when different APIs expect different units.
Data exports
Convert raw epoch columns into readable timestamps before sharing reports. Verify whether the source stored seconds or milliseconds.
Automation notes
Include both epoch and ISO values in runbooks so humans and scripts stay aligned during deployments or maintenance windows.
Copy-ready snippets
API payloads
- `"scheduled_at": 1735586400` (seconds)
- `"scheduled_at_ms": 1735586400000` (milliseconds)
Release note line
- `Release starts 17:00 UTC (epoch 1735664400 / 1735664400000ms)`
Incident timeline entry
- `T+00:00 — 1735586400 (ISO 2026-01-01T12:00:00.000Z) alert fired`
Troubleshooting common issues
Time looks off by hours
Verify whether you meant local or UTC; switch the zone toggle and compare.
API rejects the number
Confirm the expected unit. Ten digits are seconds; 13 digits are milliseconds.
Extreme values
Values beyond ~8.64e15 ms are outside JavaScript's safe date range. Recompute the intended time and try again.
DST confusion
Choose UTC for critical events near clock changes to avoid offset surprises.
Frequently asked questions
Yes. All calculations run in your browser—no data is sent anywhere.
Unix epoch time ignores leap seconds, matching common API and system behavior.
Absolutely. Enter any valid date and time; the converter returns exact epoch values.