date confusion

[djc]

I am confused with all the options for date values... What should I be using
when I want to compare (=, >, <) two dates, not including the time.. for
example when inserting data in a database the data may have the full date
and time like '12/15/2004 12:31:23 AM'. How do I convert that into just
'12/15/2004'? In other words I need to test if the current date is before or
after a stored date value, but the time does not matter.

any input is appreciated.

 

[Herfried K. Wagner [MVP]]

I am confused with all the options for date values... What should I be
using
when I want to compare (=, >, <) two dates, not including the time.. for
example when inserting data in a database the data may have the full date
and time like '12/15/2004 12:31:23 AM'. How do I convert that into just
'12/15/2004'? In other words I need to test if the current date is before
or
after a stored date value, but the time does not matter.

'If d1.Date = d2.Date Then...'.

 

[Jay B. Harlow [MVP - Outlook]]

djc,
Use DateTime.Date to get just the date part of a DateTime value.

Dim date1 As DateTime = #12/15/2004 12:31:23 AM#
Dim date2 As DateTime = #12/15/2004#

Debug.WriteLine(date1 = date2, "date1 = date2")
Debug.WriteLine(date1.Date = date2, "date1.Date = date2")

You can use DateTime.TimeOfDay to get just the time part of a DateTime
value.

Dim time1 As TimeSpan = #12:31:23 AM#.TimeOfDay

Debug.WriteLine(date1.TimeOfDay.Equals(time1), "date1 = time1")

Unfortunately the equal "=" operator is not overloaded to compare TimeSpan
values, we need to wait for VS.NET 2005 (aka Whidbey, due out later in 2005)
to allow overloading the equal operator.

' VS.NET 2005 syntax
Debug.WriteLine(date1.TimeOfDay = time1, "date1 = time1")

WARNING: Time values includes fractions of milliseconds, so be careful when
comparing them for equality (less or greater usually works better).

Hope this helps
Jay

 

[djc]

Thanks for the reply!

djc,
Use DateTime.Date to get just the date part of a DateTime value.

Dim date1 As DateTime = #12/15/2004 12:31:23 AM#
Dim date2 As DateTime = #12/15/2004#

Debug.WriteLine(date1 = date2, "date1 = date2")
Debug.WriteLine(date1.Date = date2, "date1.Date = date2")

You can use DateTime.TimeOfDay to get just the time part of a DateTime
value.

Dim time1 As TimeSpan = #12:31:23 AM#.TimeOfDay

Debug.WriteLine(date1.TimeOfDay.Equals(time1), "date1 = time1")

Unfortunately the equal "=" operator is not overloaded to compare TimeSpan
values, we need to wait for VS.NET 2005 (aka Whidbey, due out later in 2005)
to allow overloading the equal operator.

' VS.NET 2005 syntax
Debug.WriteLine(date1.TimeOfDay = time1, "date1 = time1")

WARNING: Time values includes fractions of milliseconds, so be careful when
comparing them for equality (less or greater usually works better).

Hope this helps
Jay

 

[djc]

thanks

'If d1.Date = d2.Date Then...'.