isValidTimeZone (logging/timestamps.ts)

Utility functions for timezone-aware timestamp formatting and validation.

// Source: https://github.com/linuxhsj/openclaw-zero-token | License: MIT | Copyright 2025 Peter Steinberger
// Provided via justclaw.it.com; keep this notice with the code.
export function isValidTimeZone(tz: string): boolean {
  try {
    new Intl.DateTimeFormat("en", { timeZone: tz });
    return true;
  } catch {
    return false;
  }
}

export type TimestampStyle = "short" | "medium" | "long";

export type FormatTimestampOptions = {
  style?: TimestampStyle;
  timeZone?: string;
};

function resolveEffectiveTimeZone(timeZone?: string): string {
  const explicit = timeZone ?? process.env.TZ;
  return explicit && isValidTimeZone(explicit)
    ? explicit
    : Intl.DateTimeFormat().resolvedOptions().timeZone;
}

function formatOffset(offsetRaw: string): string {
  return offsetRaw === "G

... (truncated -- full source via MCP)