ServiceNow javascript function to convert ISO8601 DateTime strings to GlideDateTime objects

ISODateTimeToGlideDateTime.js

/* function : ISODateTimeToGlideDateTime()
	Convert ISO8601 DateTime string to GlideDateTime object
*/
function ISODateTimeToGlideDateTime(s) {
	if ( (s == '') || (s == null) ) {
		return null;
	}

    // GlideDateTime constructor expects date format: 'YY-MM-DD HH::MM::SS'
    parts = s.split(/[-TZ:+]/g);
    
    if (parts.length < 6) {
    	return null;
    }

    dts = '';
	dts += parts[0] + "-" + parts[1] + "-" + parts[2];
	dts += ' ';

	// Handle sub seconds
	sec = parts[5].split(/\./);
	dts += parts[3] + ":" + parts[4] + ":" + sec[0];
	
	// Calculate timezone offset in seconds
	sign = /\d\d-\d\d:\d\d$/.test(s)? '-' : '+';
	if ( (parts[6] != null) && (parts[7] != null) ) {
		offset = parseInt(parts[6] * 3600 + parseInt(parts[7] * 60));
		offset = 0 + (sign == '-' ? -1 * offset : offset);
	} else {
		offset = 0;
	}
	
	// GlideDateTime object
	gdt = new GlideDateTime(dts);
	gdt.addSeconds(offset);
	
	return gdt;
}