Timestamp Converter
Convert Unix timestamps to human-readable dates and back. ISO 8601, RFC 2822, Excel serial, local time, relative time.
YYYY-MM-DD HH:MM:SS · local timeAbout this tool
A Unix timestamp counts the seconds that have elapsed since 1970-01-01 00:00:00 UTC (the Unix epoch). Databases, logs, APIs, and JWT exp/iat claims all store time this way because it is timezone-agnostic and trivially sortable. This converter turns a number like 1700000000 into every common human format — and back.
Type or paste either side: a timestamp in seconds (1700000000) or milliseconds (1700000000000), or a date such as 2024-01-15T12:00:00Z or 2024-01-15 12:00:00 (local time). The tool auto-detects seconds vs. milliseconds, fills the other box, and lists ISO 8601, RFC 2822, UTC, Excel serial date, local, ISO week, day-of-year, and a relative phrase like "3 days ago".
Use Share to copy a deep link with the current value embedded as ?t=… — handy for pasting into tickets, runbooks, or chat. All conversion runs locally in the browser; nothing is sent anywhere.
FAQ
How does the tool decide seconds vs. milliseconds? ›
Inputs of 12 or fewer digits are treated as seconds; 13 or more digits are treated as milliseconds. The boundary is chosen so the 10-digit timestamps common today (1 000 000 000 – 9 999 999 999) always parse as seconds.
What range of dates is supported? ›
Years 1 through 3000 are accepted. Values outside that range — including negative timestamps before the epoch and far-future ones — are rejected as out of range rather than producing misleading output.
Which date formats can I type in? ›
ISO 8601 (e.g. 2024-01-15T12:00:00Z), RFC 2822, a space-separated "YYYY-MM-DD HH:MM:SS" treated as local time, and a bare "YYYY-MM-DD" interpreted as local midnight. The native Date parser handles anything else it recognises.
Why is the relative time slightly off? ›
Relative phrases such as "2 months ago" use average lengths (30.44 days per month, 365.25 days per year), so they are approximate. For exact differences use the precise Unix or ISO values above the relative line.
What is the Excel serial date? ›
Spreadsheets (Excel, LibreOffice, Google Sheets) store datetimes as a single number: the count of days since 1899-12-30, with the fractional part representing the time of day. The "Excel serial" row shows that number, so you can paste a timestamp straight into a cell or read a serial value back from a CSV export. Example: 2024-01-15 12:00:00 UTC ≈ 45306.5.