Creates idle periods for multiple meters.

• A meter is considered to be active outside of the idle periods.
• The given idle periods are added to already existing idle periods.
• A meter may occur only once in the enrollment array.
• If there is an overlap between an existing idle/disenroll period and a new idle period, the given idle period overrides the existing idle/disenroll period for the overlapping period range.
• If one of the date ranges in the array is invalid, the entire POST request is discarded and an error is returned. No period will be added, even if other periods in the same body are valid.
• Changes are applied if at least one meter can be found. Idle periods for unknown meters are discarded.
• All dates respect the timezone the meter is in.