Epoch & Unix Timestamp Converter

Understanding Unix Timestamps and the Epoch

The Unix epoch is the universal reference point used across operating systems, distributed databases, cloud APIs, and programming runtimes to measure time independently of geographical time zones and daylight saving time (DST) shifts.

Seconds vs. Milliseconds vs. Microseconds

When debugging API payloads or database records, identifying the unit of measurement is the most common hurdle:

Unit	Number of Digits	Example	Common Runtime / Use Case
Seconds	10 digits	1742400000	Linux CLI, Unix kernel, Redis, JWT expiry
Milliseconds	13 digits	1742400000000	JavaScript, Java, MongoDB ISODate
Microseconds	16 digits	1742400000000000	Python datetime, Cassandra, PostgreSQL
Nanoseconds	19 digits	1742400000000000000	Go time.Now().UnixNano(), InfluxDB

Common Conversion Snippets

• JavaScript / Node.js:

  // Current epoch seconds
  const sec = Math.floor(Date.now() / 1000);
  // Epoch to Date
  const date = new Date(1742400000 * 1000);

• Python 3:

  import time
  from datetime import datetime, timezone
  # Epoch to UTC string
  utc_time = datetime.fromtimestamp(1742400000, tz=timezone.utc)

• PostgreSQL:

  SELECT TO_TIMESTAMP(1742400000);