When setting limits, these can be set daily, weekly or monthly.
These limits are as followed :
Daily - A day starts at 00:00 UTC and ends at 23.59 UTC/GMT
Weekly - A calendar week begins at 00:00 UTC/GMT every Monday morning.
Monthly - A month starts at 00:00 UTC/GMT on the 1st and will run until 23:59 UTC on the last day (28/29th, 30th or 31st).