Qrono: JavaScript Date Manipulation Library Demos

Handle date-only values, immutable date math, UTC parsing, and DST transitions with the Qrono JavaScript library.

Factory and conversion

Build the same instant from several inputs.

Change the source value and see string, object, array, native Date, timestamp, accessor, and immutable setter output update together.

Date-time string

Accepts ISO-like strings with either a space or T between date and time.

Set hour

Set minute

Calculation and boundaries

Qrono treats calendar fields literally while time fields behave as durations, which keeps end-of-month work predictable.

Base value

Months to add

Days to add

Hours to subtract

Minutes to subtract

QronoDate

This section uses qrono.date() for ISO week numbers, leap-year data, month length, year length, and date-only arithmetic.

Date

Years to add

Days to subtract

Comparison

The comparison methods work against other Qrono instances, native Date objects, and numeric timestamps.

First value

Second value

Value to test between them

Context and DST

Local mode uses the browser environment. Daylight-saving metrics depend on the time zone of the browser that opens this page.

Local test value

Disambiguation

The reject option displays an inline error when the browser reports a skipped or repeated local time.

Validation

The demo catches errors from invalid values and leaves the page responsive.

Try a value

Waiting for input