/**
* Timezone conversion utilities
*/
export interface ConvertTimezoneArgs {
datetime: string;
from_timezone?: string;
to_timezone: string;
format?: string;
}
export interface ConvertTimezoneResult {
input_datetime: string;
from_timezone: string;
to_timezone: string;
converted_datetime: string;
iso_string: string;
unix_timestamp: number;
formatted: string;
}
/**
* Convert datetime between timezones
*/
export function convertTimezone(args: ConvertTimezoneArgs): ConvertTimezoneResult {
const {
datetime,
from_timezone = 'UTC',
to_timezone,
format,
} = args;
if (typeof datetime !== 'string' || datetime.trim().length === 0) {
throw new Error('Datetime must be a non-empty string');
}
if (typeof to_timezone !== 'string' || to_timezone.trim().length === 0) {
throw new Error('Target timezone must be a non-empty string');
}
try {
// Parse input datetime
let inputDate: Date;
// Try to parse as ISO string first
if (datetime.includes('T') || datetime.includes('Z') || datetime.includes('+')) {
inputDate = new Date(datetime);
} else {
// Try common formats
inputDate = new Date(datetime);
}
if (isNaN(inputDate.getTime())) {
throw new Error(`Invalid datetime format: ${datetime}`);
}
// Get datetime string in source timezone
const sourceDateString = inputDate.toLocaleString('en-US', {
timeZone: from_timezone,
year: 'numeric',
month: '2-digit',
day: '2-digit',
hour: '2-digit',
minute: '2-digit',
second: '2-digit',
hour12: false,
});
// Convert to target timezone
const targetDateString = inputDate.toLocaleString('en-US', {
timeZone: to_timezone,
year: 'numeric',
month: '2-digit',
day: '2-digit',
hour: '2-digit',
minute: '2-digit',
second: '2-digit',
hour12: false,
});
// Create a new date object representing the time in target timezone
// We need to construct a date string that represents the same moment in target timezone
const targetDate = new Date(inputDate.toLocaleString('en-US', { timeZone: to_timezone }));
// Get ISO string
const isoString = targetDate.toISOString();
// Get Unix timestamp (always UTC)
const unixTimestamp = Math.floor(inputDate.getTime() / 1000);
// Format according to requested format or default
let formatted: string;
if (format) {
// Custom format using Intl.DateTimeFormat
const formatter = new Intl.DateTimeFormat('en-US', {
timeZone: to_timezone,
year: 'numeric',
month: '2-digit',
day: '2-digit',
hour: '2-digit',
minute: '2-digit',
second: '2-digit',
hour12: false,
});
formatted = formatter.format(inputDate);
} else {
formatted = targetDateString;
}
return {
input_datetime: datetime,
from_timezone: from_timezone || 'UTC',
to_timezone,
converted_datetime: targetDateString,
iso_string: isoString,
unix_timestamp: unixTimestamp,
formatted,
};
} catch (error) {
throw new Error(`Timezone conversion failed: ${error instanceof Error ? error.message : String(error)}`);
}
}
