String dd = '2022-05-01 12:00:00';
Date dt1 = date.valueOf(dd);
Date dt2;
system.debug('dt1----->'+(dt1>dt2));
system.debug('dt1--2--->'+(dt2>dt1));
Datetime dt3 = Datetime.now();
String dt3Str = dt3.format('yyyyMMdd HHmmss');
system.debug('dt1--3--->'+dt3Str);