subtractHours method
Subtracts the specified number of hours from the current DateTime.
Args: hours (int): The number of hours to subtract.
Returns: DateTime: A new DateTime object with the subtracted hours.
Implementation
DateTime subtractHours(int hours) {
if (hours == 0) {
// same
return this;
}
// We used the Jiffy package to add years, months, etc
// https://stackoverflow.com/questions/54792056/add-subtract-months-years-to-date-in-dart
return Jiffy.parseFromDateTime(this).subtract(hours: hours).dateTime;
}