Unix Timestamp to Date Converter

How timestamp-to-date conversion works

A Unix timestamp counts seconds from 1970-01-01 00:00:00 UTC, so converting it to a date is pure arithmetic: divide by 86,400 to find the day number since the epoch, map that to a calendar date, and use the remainder for the time of day. Timezone and daylight-saving rules then shift the display — never the instant itself.

// JavaScript — seconds to Date
new Date(1758000000 * 1000).toISOString();
// "2025-09-16T05:20:00.000Z"

// Python
from datetime import datetime, timezone
datetime.fromtimestamp(1758000000, timezone.utc)
# datetime(2025, 9, 16, 5, 20, tzinfo=timezone.utc)

// PHP
gmdate('Y-m-d H:i:s', 1758000000);
// "2025-09-16 05:20:00"

Which unit is my timestamp?

Count the digits. For dates in the current era:

• 10 digits — seconds (C, PHP, Python, Go, most REST APIs)
• 13 digits — milliseconds (JavaScript, Java, Kotlin)
• 16 digits — microseconds (PostgreSQL, distributed traces)
• 19 digits — nanoseconds (Go UnixNano(), Linux kernel)

The auto-detection above uses these magnitude ranges rather than a blind digit count, and negative timestamps are supported for pre-1970 dates.

Timestamp to date examples