function toPersian(oGregorian) {
		var iJulianDayNumber = g2d(oGregorian.year, oGregorian.month + 1, oGregorian.day);
		return d2j(iJulianDayNumber);
	}
Calculate Persian date from gregorian

@param {object} oGregorian a JS object containing day, month and year in the gregorian calendar
@private