JavaScript Temporal vs Date
Compare JavaScript Temporal vs Date.
Learn the differences in mutation, time zones, DST handling, and date math.
Learn why Temporal is the modern alternative to Date.
Differences Between Date and Temporal
| Feature | Date | Temporal |
|---|---|---|
| Created | 1995 | 2026 |
| Time zone support | Limited | Built-in |
| Immutable | No | Yes |
| Date-Only Type | No | Yes |
| Time-Only Type | No | Yes |
| 1-Based Months | No | Yes |
| DST safe arithmetic | No | Yes |
| RFC 5545 iCalendar | No | Yes |
| Modern API design | No | Yes |
| Precisition | Milliseconds | Nanoseconds |
Note
The JavaScript Date object has been used since 1995.
Temporal is the modern replacement designed to fix many of Date's problems.
Mutability vs Immutability
Date objects can change. They are mutable.
This can cause unexpected side effects.
Date Example
// Create a Date
let d = new Date(2026, 5, 17);
// Add 7 days
d.setDate(d.getDate() + 7);
// Here original date is gone
Try it Yourself »
Temporal objects cannot change. They are immutable.
Operations return a new value instead.
Temporal Example
// Create a Date
let d = Temporal.PlainDate.from("2026-05-17");
// Add 7 days
let next = d.add({ days: 7 });
// Here original date is kept
Try it Yourself »
Date and Time Zone
new Date(2026, 4, 1) creates a timestamp of your local time zone at midnight.
This means a day can "shift" when you format it in UTC or in another zone.
Example
// Months are 0-based (4 = May)
const d = new Date(2026, 4, 1);
// Might be 2026-04-30T22:00:00.000Z in some time zones:
d.toISOString();
Try it Yourself »
Handling Time Zones
Date mixes local time and UTC.
This makes time zone handling confusing.
Date Example
let d = new Date();
let time1 = d.toString();
let time2 = d.toUTCString();
Try it Yourself »
Temporal uses clear types for time zones.
ZonedDateTime always includes a time zone.
Date Parsing is Inconsistent
new Date("2026-05-01") parses as an instant as UTC in modern JS,
but historically it has been a minefield of different formats, browser quirks and locale surprises.
Temporal avoids this by:
- defining strict parsing rules for ISO strings
- using Temporal.Instant.from() for clearly-typed conversions
Temporal.PlainDate is not a timestamp.
It is just "2026-05-01" with no time and no time zone, so there can not be any shifting.
Temporal is 1-Based
- Date: January = 0
- Temporal: January = 1 (much more human-friendly)
Example
// May 1:
new Date(2026, 4, 1)
// May 1:
new Temporal.PlainDate(2026, 5, 1)
Date Math
Date math with Date often requires manual calculations.
Date Example
let start = new Date("2026-05-17");
start.setDate(start.getDate() + 30);
Try it Yourself »
Temporal has built-in date arithmetic.
Temporal Example
let start = Temporal.PlainDate.from("2026-05-17");
let result = start.add({ days: 30 });
Try it Yourself »
Nanosecond Precision
Unlike the Date object which uses milliseconds, Temporal.Instant offers 1000 times higher nanosecond precision.
Clear Separation of Types
Date represents both a date and a time in one object.
Temporal separates different use cases into different types.
| Object | Description |
|---|---|
Temporal.Now | Current time (UTC timestamp) |
Temporal.Instant | Exact moment in time (UTC timestamp) |
Temporal.PlainDate | Plain date only (year, month, day) |
Temporal.PlainTime | Plain time without a time zone |
Temporal.PlainDateTime | Date and time without a time zone |
Temporal.ZonedDateTime | Date and time with a time zone |
Temporal.Duration | Length of time (days, hours, minutes) |
This makes code easier to read and less error-prone.
When to Use Date?
You may still use Date for simple tasks such as getting a quick timestamp.
You may also need it if you support older environments without Temporal.
When to Use Temporal?
You need correct time zone handling.
You work with international users.
You want safe date arithmetic.
You want clear and modern code.
Date works, but it has limitations and confusing behavior.
Temporal is safer, clearer, and designed for modern applications.
