Npgsql.EntityFrameworkCore.PostgreSQL.NodaTime for storing appropriate types.DateTimeOffset for their creation date and time - always stored in UTC as I believe EFCore cannot store DateTimeOffsets with a non-UTC offset. I'm unsure whether to use OffsetDateTime, ZonedDateTime, or Instant.DateTimeOffset for when the timer "expires". See the linked thread for issues related to Daylight Savings Time - I believe I will need to store a LocalTime or Instant and convert it to the user's timezone at runtime (see next point)TimeZoneInfo instead of TimeSpan which I previously used.