Timestamp Converter

What is a Unix Epoch Timestamp?

A Unix Timestamp (also known as Epoch time or POSIX time) is a system for describing a specific point in time. It is defined as the total number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970, minus leap seconds.

Why do developers use it?

Storing dates naturally (e.g., "October 14th, 2023 at 5:00 PM EST") in a database is highly problematic. Different regions format dates differently (MM/DD/YYYY vs DD/MM/YYYY), and handling global timezone conversions mathematically using string data is incredibly processing-heavy and prone to errors.

By storing time instead as a single 32-bit or 64-bit integer, developers solve all of these issues instantly:

• Timezones are Eliminated: Because the Epoch strictly anchors to UTC, a timestamp of 1700000000 represents the exact same absolute moment in time regardless of whether the server is located in Tokyo, London, or New York. The conversion to the local timezone happens dynamically on the user's client side (in their browser).
• Faster Database Checks: Sorting integers (finding the oldest or newest post on a forum) is mathematically much faster for SQL databases than attempting to parse and sort text-based date strings.

Seconds vs Milliseconds

By strict definition, the Unix Epoch is calculated in seconds. This is the standard for PHP servers and MySQL databases. However, Javascript natively calculates Epoch time in milliseconds (1/1000th of a second). If a timestamp looks abnormally long (13 digits instead of 10 digits), it is highly likely you are looking at a millisecond timestamp.