discord-timestamp-kit

Make Discord timestamp codes like <t:1798765200:F>, which every reader sees in their own time zone. The kit also converts a date and time in any IANA time zone to Unix seconds without DST bugs, accepts Unix input in seconds or milliseconds, and decodes Discord snowflake IDs into the moment they were created. It is pure TypeScript with zero dependencies and no DOM, so it runs in browsers, Workers, Deno, Bun and Node 22+.

Powers https://discordtimestampgen.com. If you'd rather not bundle a library, the same engine is also a free JSON API: https://discordtimestampgen.com/developers

Use

npm install discord-timestamp-kit

Make a <t:unix:F> code

import { buildTimestampCode, DISCORD_FORMATS } from 'discord-timestamp-kit';

buildTimestampCode(1798765200, 'F');   // '<t:1798765200:F>'

for (const f of DISCORD_FORMATS) {
  console.log(f.code, f.label, buildTimestampCode(1798765200, f.code));
}
// t Short Time       <t:1798765200:t>
// T Long Time        <t:1798765200:T>
// d Short Date       <t:1798765200:d>
// D Long Date        <t:1798765200:D>
// f Short Date/Time  <t:1798765200:f>
// F Long Date/Time   <t:1798765200:F>
// R Relative Time    <t:1798765200:R>

Convert a local date and time in a time zone to Unix

import { dateTimeToUnixInTz, buildTimestampCode } from 'discord-timestamp-kit';

// 8 PM on New Year's Eve in New York
const unix = dateTimeToUnixInTz('2026-12-31', '20:00', 'America/New_York'); // 1798765200
buildTimestampCode(unix!, 'R');   // '<t:1798765200:R>'

The inputs use the same YYYY-MM-DD and HH:mm strings that <input type="date"> and <input type="time"> produce. The time-zone offset is sampled twice, the second time at the instant being returned, so times in the hours around a DST change don't come out an hour off. Pass 'UTC' for UTC. Leave the zone out to use the runtime's own zone. The function returns null for blank or malformed input. An unknown zone name falls back to the runtime's zone.

Parse a pasted Unix timestamp (seconds or milliseconds)

import { parseUnixInput } from 'discord-timestamp-kit';

parseUnixInput('1798765200');      // { unix: 1798765200, wasMs: false }
parseUnixInput('1798765200000');   // { unix: 1798765200, wasMs: true }
parseUnixInput('12.5');            // null (integers only)

Any value of 100,000,000,000 or more is treated as milliseconds. In seconds, that would be a date in the year 5138.

Decode a Discord snowflake

import { decodeSnowflake } from 'discord-timestamp-kit';

const s = decodeSnowflake('175928847299117063');
// { unixMs: 1462015105796, unixSeconds: 1462015105, workerId: 1, processId: 0, increment: 7 }
new Date(s!.unixMs).toISOString();   // '2016-04-30T11:18:25.796Z'

Message, user, channel and server IDs are all snowflakes. The bit math uses BigInt, so IDs above Number.MAX_SAFE_INTEGER decode exactly. Pass the ID as a string.

Preview what Discord will show

import { renderDiscordPreview } from 'discord-timestamp-kit';

renderDiscordPreview(1798765200, 'F');                 // e.g. 'Thursday, December 31, 2026 8:00 PM'
renderDiscordPreview(1798765200, 'R', 1798758000);     // 'in 2 hours'

The preview uses Discord's en-US layout, in the runtime's local time zone. The R format takes an optional "now", in Unix seconds.

API

Export	What it does
DISCORD_FORMATS	The 7 format codes (t T d D f F R) with label, description and example
buildTimestampCode(unix, code)	Returns <t:unix:code>
dateTimeToUnixInTz(date, time, timeZone?)	Converts a wall-clock date and time in an IANA zone to Unix seconds, DST-safe
parseUnixInput(raw)	Parses an integer string in seconds or milliseconds, or returns null
decodeSnowflake(raw)	Returns { unixMs, unixSeconds, workerId, processId, increment }, or null
renderDiscordPreview(unix, code, now?)	Returns the text Discord's English client would show

Types: DiscordFormat, DiscordFormatCode, DecodedSnowflake.

Tests

npm test   # 23 engine checks: DST boundaries in New York, London and Sydney, half-hour offsets, ms detection, Discord's documented snowflake example

License

MIT