datetime

Convert timestamps and dates between many formats at once with live sync and shareable permalinks.

Overview

datetime is a browser-based date and time converter. Enter any timestamp or date string and all twelve output formats update instantly. No server involved — everything runs in the browser using the built-in Date API.

Input formats

The parser accepts any of the following:

• Unix seconds — a 10-digit integer, e.g. 1705312200
• Unix milliseconds — a 13-digit (or longer) integer, e.g. 1705312200000
• ISO 8601 — e.g. 2024-01-15T10:30:00Z or 2024-01-15T10:30:00.000Z
• Any string parseable by `new Date()` — e.g. January 15 2024, Mon Jan 15 2024 10:30:00 GMT+0000

For pure integer inputs, the parser uses digit count to decide the interpretation:

// 13+ digits → treat as milliseconds
new Date(n);

// fewer digits → treat as seconds
new Date(n * 1000);

If the input cannot be parsed, the grid clears and the badge shows Invalid.

Output formats

The Local row reflects your browser's local timezone. All other rows use UTC.

Now

Click Now to fill the input with the current Unix millisecond timestamp. All output rows update immediately to reflect the current moment.

Live mode

Toggle Live OFF → Live ON in the input row to enter live mode. In live mode:

• The input field is disabled
• All output rows update every 200ms to reflect the current time
• The badge shows Live

Turn live mode off to return to manual input. The previous input value is restored if it's still in the URL, otherwise the field will be empty.

Relative live mode

The Relative row has its own Live OFF / Live ON toggle. When enabled, only the relative value updates — every second — while all other rows remain anchored to the parsed date.

This is useful for watching a fixed timestamp age in real time without updating the rest of the grid.

When global live mode is on, the relative live toggle shows Live Unavailable and is disabled — global live refreshes all rows continuously, so the relative time is always 0 seconds.

Copying values

Each row has a Copy button. Click it to copy that row's value to your clipboard. The button briefly shows Copied! as confirmation, then resets after 1.5 seconds.

Permalinks

The URL updates live as you type. A single query parameter is used:

• value — the raw input string as entered

Example permalinks

/datetime?value=1705312200

Loads with the Unix seconds timestamp 1705312200 pre-parsed.

/datetime?value=2024-01-15T10%3A30%3A00Z

Loads with the ISO 8601 string 2024-01-15T10:30:00Z pre-parsed.

Share or bookmark the URL to return to the same date. The input and all output rows are restored on load.

Use the Copy button in the Permalink row to copy the current URL to your clipboard.

Use the Reset button to clear the input, collapse all output rows, and return the URL to the bare /datetime path.