Dates are number that are formated to look like a string Date. As long as
the dates are Not strings there should be no problems. To verify you have
dates clciik ona cell and then go to worksheet menu Format - Cells - Number
and check that a date format is highlighted.
The only problem you may encounter is that dates with hidden Hours and
minutes will sort in sequence includiing the hours and minutes.
Time is stored as a number with 1 = 1/1/1900. each day is = 1. So 2 =
1/2/1900. An hour = 1/24 starting at midnight. So 8:00 AM = 8/24 = 1/3 =
..3333. 1/1/1900 8:00 AM = 1.33333333333. Minutes are 1/(24 * 60). Seconds
are 1/(24 * 60 * 60).
If the number is 1.333333 (1/1/1900 8:00 AM) and the format for the cell is
showing only Month, day, Year you will not see the hours and minutes but the
number is still 1.333333. If the Date is 1.666666 (1/1/1900 2:00 PM) the
8:00 AM will appear before the 2:00 PM even though you only see the Date
(Month, Day, year). so if you had
John 1/1/1900 8:00 AM
Mary 1/1/1900 2:00 PM
and your sorted using two keys Date first, Name Second you would get
Mary 1/1/1900 (=1.33333)
John 1/1/1900 (=1.66666)
The dates wouild appear identical but are not)