Check if a date is between two dates

Test whether a YYYY-MM-DD date falls inside an inclusive range.

JavaScript Version 1.0.0 · MIT · .md

function isBetween({ date, min, max }) { const time = Date.parse(date); return time >= Date.parse(min) && time <= Date.parse(max); }

Input & expected output

{
  "date": "2026-10-28",
  "min": "2026-10-01",
  "max": "2026-10-31"
}

true

The edge case

{
  "date": "2026-11-01",
  "min": "2026-10-01",
  "max": "2026-10-31"
}

false

Know the limits

• Both ends are included. Dates are UTC calendar days, so the machine’s time zone does not matter.

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.

Keep exploring

• Check whether all values are equal — Compare every item with the first using Object.is.
• Check whether an object is empty — Check for own enumerable string keys on a JSON object.
• Check whether an integer is even — Test parity for safe integers, including zero and negative values.