Fiscal Quarter (QN YYYY or YYYY QN) Regex for Go

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching fiscal quarter (qn yyyy or yyyy qn), 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

// Fiscal Quarter (QN YYYY or YYYY QN)
// ReDoS-safe | RegexVault — Localization > Date Formats

package validation

import "regexp"

var fiscalQuarterQnYyyyOrYyyyQnRe = regexp.MustCompile(`^(?:(Q[1-4])\s+((?:19|20)[0-9]{2})|((?:19|20)[0-9]{2})\s+(Q[1-4]))$`)

func ValidateFiscalQuarterQnYyyyOrYyyyQn(s string) bool {
    return fiscalQuarterQnYyyyOrYyyyQnRe.MatchString(s)
}

// Example
// fmt.Println(ValidateFiscalQuarterQnYyyyOrYyyyQn("Q1 2024")) // true

Test Cases

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

Technical Notes

Capture groups: 1=quarter (QN format), 2=year (QN format), 3=year (YQ format), 4=quarter (YQ format). Fiscal quarters may not align with calendar quarters — Q1 may start in January, April, July, or October depending on the company's fiscal year.