The start of the time period included in these statistics.
- iOS 8.0+
- Mac Catalyst 13.0+Beta
- watchOS 2.0+
This property contains the start date for the statistics. If you calculated these statistics using a statistics query, this is the earliest start date from all the samples that match the query. If you calculated these statistics using a statistics collection query, this is the start of the time interval for that particular collection of statistics.