tz-offset

/** * @typedef {import('tz-offset')} TZOffset */ /** * A basic example demonstrating the use of tz-offset for timezone calculations. * Note: This package is very old and likely abandoned. Consider modern alternatives. */ function demonstrateTzOffset() { // For CommonJS environments (Node.js) /** @type {TZOffset} */ const tzOffset = require('tz-offset'); // Get the offset for a specific timezone (e.g., America/Sao_Paulo) // Returns the offset in minutes. Sao Paulo is UTC-3, so 3 * 60 = 180. // Note: This value might not account for DST accurately in a historical context. const saoPauloOffset = tzOffset.offsetOf("America/Sao_Paulo"); console.log(`Offset for America/Sao_Paulo: ${saoPauloOffset} minutes`); // Expected: 180 // Remove the timezone offset from a given date const now = new Date(); const dateWithoutOffset = tzOffset.removeOffset(now); console.log(`Original Date: ${now.toISOString()}`); console.log(`Date without local offset: ${dateWithoutOffset.toISOString()} (Note: This creates a new Date object representing the same 'wall-clock' time but in UTC, effectively removing the local offset).`); // Represent a given date in another timezone const referenceDate = new Date('2023-10-27T10:00:00Z'); // A UTC date const londonTime = tzOffset.timeAt(referenceDate, "Europe/London"); console.log(`Reference Date (UTC): ${referenceDate.toISOString()}`); console.log(`Equivalent time in Europe/London: ${londonTime.toISOString()}`); // Will show the date as if it were in London's timezone } demonstrateTzOffset();