Dates & Timesflags: g

European Date Format (DD/MM/YYYY)

Match European-style dates in DD/MM/YYYY format with valid day (01–31) and month (01–12) ranges.

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("(?:0[1-9]|[12]\\d|3[01])\\/(?:0[1-9]|1[0-2])\\/\\d{4}", "g");
const input = "15/01/2024";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).

Python (re) code

pyPython

import re

pattern = re.compile(r"(?:0[1-9]|[12]\d|3[01])\/(?:0[1-9]|1[0-2])\/\d{4}")
input_text = "15/01/2024"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`(?:0[1-9]|[12]\d|3[01])\/(?:0[1-9]|1[0-2])\/\d{4}`)
	input := `15/01/2024`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.

Pattern

regexengine-agnostic

(?:0[1-9]|[12]\d|3[01])\/(?:0[1-9]|1[0-2])\/\d{4}   (flags: g)

Raw source: (?:0[1-9]|[12]\d|3[01])\/(?:0[1-9]|1[0-2])\/\d{4}

How it works

Day alternation covers 01–31, month covers 01–12, year is any 4-digit number. Slashes are literal. Does not detect impossible combinations like 31/02/2024.