DateBounds
DateBounds[{date1,date2,…}] gives the earliest and latest of the datei.
DateBounds[tseries] gives the first and last dates in the time series tseries.
DateBounds[bin] gives the first and last time stamps in the databin bin.
DateBounds[interval] gives the start and end dates of the date interval interval.
DateBounds[interval,gran] gives the endpoints of interval in the specified granularity gran.
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