Reset all of the remaining time units

You can insert an exclamation into the DateTime::createFromFormat() method to reset all of the remaining time units

// 2021-10-12 21:48:07.0
DateTime::createFromFormat('Y-m-d', '2021-10-12');
 
// 2021-10-12 00:00:00.0
DateTime::createFromFormat('!Y-m-d', '2021-10-12');
 
// 2021-10-12 21:00:00.0
DateTime::createFromFormat('!Y-m-d H', '2021-10-12');

Tip given by @SteveTheBauman