This function returns
True if timestamp lies inside
the part of day containing base_timestamp
up until and including the exact millisecond of base_timestamp.
The date and time that you want to compare with base_timestamp.
base_timestamp
Date and time that is used to evaluate the timestamp.
period_no
The day can be offset by period_no.
period_no is an integer, where the
value 0 indicates the day which contains base_timestamp.
Negative values in period_no indicate
preceding days and positive values indicate succeeding days.
day_start
(optional) If you want
to work with days not starting midnight, indicate an offset as a
fraction of a day in day_start,
For example, 0.125 to denote 3 AM.