Get the tomorrow date

Add one calendar day in UTC.

JavaScript Version 1.0.0 · MIT · .md

function tomorrow(date) { const d = new Date(date); d.setUTCDate(d.getUTCDate() + 1); return d.toISOString().slice(0, 10); }

Try in the local lab Download function

Input & expected output

Input

"2026-10-28"

Expected output

"2026-10-29"

The edge case

Input

"2026-12-31"

Expected output

"2027-01-01"

Know the limits

The original’s second variant added 24 hours, which is not one day across a daylight-saving change.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Source & maintenance

Adds a calendar day in UTC; the original's second variant added 24 hours. Original MDX retained as inert source evidence.

Maintained by Oveyon. Source commit: 14b481cf60df. Read the license.

Local fixture scope · Node.js 22.23.2 · reviewed October 28, 2026. No external service is required.

Keep exploring

Compare two dates — Compare validated ISO calendar dates in UTC and return -1, 0 or 1.
Add AM PM suffix to an hour — Turn an hour from 0 to 23 into a 12-hour label with am or pm.
Calculate the number of days between two dates — Count whole calendar days between two YYYY-MM-DD dates.