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Timestamp ⇄ Datetime
Convert Unix epochs to human dates and back
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Background
Why everyone uses Unix epoch
A Unix timestamp is the number of seconds since midnight UTC on January 1, 1970. One scalar, no timezone surprises, no leap-second drama. Databases store it as an integer, APIs ship it as a number, and clients format it however they want — usually in the user's local timezone via Date() or equivalent.
epoch.js
const now = Math.floor(Date.now() / 1000)
// 1780334595
const human = new Date(now * 1000)
// 2026-06-01 17:23:15 UTC
2³¹
Y2038 limit (signed 32-bit)
UTC
Always
1970
Unix epoch
0
Timezone bugs