use Nilambar\NepaliDate\NepaliDate;
$obj = new NepaliDate();
// Convert BS to AD.
$date = $obj->convertBsToAd('2077', '1', '1');
// Convert AD to BS.
$date = $obj->convertAdToBs('2020', '1', '1');
// Get Nepali date details by BS date.
$date = $obj->getDetails('2077', '1', '1', 'bs');
// Get Nepali date details by AD date.
$date = $obj->getDetails('2020', '1', '1', 'ad');