Timestamp Converter

Unix timestamp (also called epoch time): seconds (or milliseconds, or microseconds) since 1970-01-01 00:00:00 UTC. Just a number: 1760000000.

ISO 8601: human-readable datetime string with explicit timezone: 2025-10-09T08:53:20Z.

• Use Unix timestamp for storage, cross-language serialization, arithmetic (elapsed time), sorting, database indexes. Integers compare fast.
• Use ISO 8601 for log files, API responses visible to humans, debugging, APIs documented for external consumers.
• Never use local timezone formatting in storage or APIs. Always UTC or explicit offset. Many production bugs are stamped local-time.

Common mistake: storing seconds in one table and milliseconds in another. Always pick one precision per column and document it.

Discord renders <t:UNIX_TIMESTAMP:FORMAT> as a localized, relative or absolute time for every viewer. Their timezone, their locale.

Announce an event across a global community? Use <t:UNIX:F> and every member sees their own local time.

# Python
import time, datetime
time.time()                           # 1760000000.123  (float seconds since epoch)
int(time.time())                      # 1760000000      (seconds)
int(time.time() * 1000)               # milliseconds
datetime.datetime.fromtimestamp(1760000000, tz=datetime.timezone.utc).isoformat()

// JavaScript / TypeScript
Date.now()                            // milliseconds since epoch
Math.floor(Date.now() / 1000)         // seconds
new Date(1760000000 * 1000).toISOString()  // "2025-10-09T08:53:20.000Z"

// Java (JDK 8+)
Instant.now().getEpochSecond();       // seconds
Instant.now().toEpochMilli();         // milliseconds
Instant.ofEpochSecond(1760000000).toString();

// Go
time.Now().Unix()                     // seconds
time.Now().UnixMilli()                // milliseconds
time.Unix(1760000000, 0).Format(time.RFC3339)

// C# / .NET
DateTimeOffset.UtcNow.ToUnixTimeSeconds()
DateTimeOffset.UtcNow.ToUnixTimeMilliseconds()
DateTimeOffset.FromUnixTimeSeconds(1760000000).ToString("O")

The year-2038 problem: 32-bit signed Unix timestamps overflow on 2038-01-19 03:14:07 UTC. All modern platforms use 64-bit timestamps (valid until the year 292,277,026,596). Old embedded systems and some legacy databases still use 32-bit — audit before the next decade.