This is something that was deeply regretted later, but it serves the request in the question.

In database layer, Date Time components are stored in separate columns as integers (Year | Month | Day | Hour | Min). This way, it is possible to add, remove time (mostly through a custom function) and everything is stored without the timezone info.

Due to working with integer, it is quicker then parsing strings.

Regret came later, when we built additional functionality over this, and it was a nightmare to parse these data back into proper DateTime. Therefore I suggest to store at least the date time ticks as an additional info.