REGEXVAULTv2.0
Localization/Date Formats
Verified Safe

Korean Date Format (YYYY년 MM월 DD일) Regex for Go

/^((?:19|20)[0-9]{2})\s?(0?[1-9]|1[0-2])\s?(0?[1-9]|[12][0-9]|3[01])$/

What this pattern does

This page provides a well-structured, multi-part regular expression for matching korean date format (yyyy년 mm월 dd일), ported and verified for Go. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

Go
// Korean Date Format (YYYY년 MM월 DD일)
// ReDoS-safe | RegexVault — Localization > Date Formats

package validation

import "regexp"

var koreanDateFormatYyyyMmDdRe = regexp.MustCompile(`^((?:19|20)[0-9]{2})년\s?(0?[1-9]|1[0-2])월\s?(0?[1-9]|[12][0-9]|3[01])일$`)

func ValidateKoreanDateFormatYyyyMmDd(s string) bool {
    return koreanDateFormatYyyyMmDdRe.MatchString(s)
}

// Example
// fmt.Println(ValidateKoreanDateFormatYyyyMmDd("2024년 1월 15일")) // true

Test Cases

Matches (Valid)
Rejects (Invalid)
2024년 1월 15일2024년 13월 15일
2024년1월15일2024년 1월 32일
1999년 12월 31일2024/01/15
2024년 3월 1일2024-01-15

When to use this pattern

This pattern is drawn from the Localization > Date Formats category and carries a ReDoS-safe certification. That matters for Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

North Korea uses the Juche calendar (starting 1912, the birth year of Kim Il-sung). Juche 113 = 2024. South Korea uses the standard Gregorian calendar.

Technical Notes

Korean uses 년 (year), 월 (month), 일 (day). Spaces between the components are optional. The optional \s? handles both spaced and unspaced forms. Korea uses the Gregorian calendar exclusively for civil purposes.

Have a pattern that belongs in the vault?

Submit it for review — community-verified patterns get credited to your GitHub handle. Free submissions join the queue. Priority review available for $15.

Submit a Pattern