const start =
parseTimestamp("2026-06-08")
const next =
addToDate(start, { day: 7 })
start !== next
formatTimestamp(next)Framework Agnostic
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Timestamp
Immutable date, time, interval, and range helpers for JavaScript and TypeScript.
Parse, compare, and compose immutable date and time objects without binding your app to a UI framework, browser timezone surprise, or heavyweight date runtime.
ImmutableISO parsingSSR-friendlyESMZero UI dependency
Deterministic CoreBrowser + Node + SSR
Why It Exists
Small primitives for dates that need to behave the same everywhere
Timestamp is meant to sit underneath UI components, API clients, docs examples, tests, and server-rendered apps without bringing framework assumptions along for the ride.
event
Date + Time Objects
Represent date-only, time-only, and date-time values with explicit fields instead of hidden mutable Date state.
sync_alt
Safe Date Math
Add, compare, diff, clamp, and validate values while returning fresh timestamp objects each time.
travel_explore
Runtime Agnostic
Use the same helpers in browsers, Node.js, SSR, serverless, edge runtimes, Vue, React, or plain TypeScript.
schedule
Intervals + Workweeks
Build predictable calendar structures such as day lists, intervals, weekdays, month labels, and workweek ranges.
verified
Deterministic Testing
Prefer caller-provided values and explicit UTC helpers when server/client timezone differences matter.
extension
Room to Grow
Calendar adapters, instant conversion, range math, and duration helpers can grow without tying the core to a UI framework.
Design Model
Wall-clock friendly first, explicit instant conversion when needed
ISO strings with seconds, milliseconds, and timezone suffixes can be parsed today. The suffix is stored instead of silently converting the value, while instant helpers let apps convert wall-clock selections into UTC storage when they need a shared moment in time.
API Map