DateTime.ToString() Patterns

MM/dd/yyyy 08/22/2006
dddd, dd MMMM yyyy Tuesday, 22 August 2006
dddd, dd MMMM yyyy HH:mm Tuesday, 22 August 2006 06:30
dddd, dd MMMM yyyy hh:mm tt Tuesday, 22 August 2006 06:30 AM
dddd, dd MMMM yyyy H:mm Tuesday, 22 August 2006 6:30
dddd, dd MMMM yyyy h:mm tt Tuesday, 22 August 2006 6:30 AM
dddd, dd MMMM yyyy HH:mm:ss Tuesday, 22 August 2006 06:30:07
MM/dd/yyyy HH:mm 08/22/2006 06:30
MM/dd/yyyy hh:mm tt 08/22/2006 06:30 AM
MM/dd/yyyy H:mm 08/22/2006 6:30
MM/dd/yyyy h:mm tt 08/22/2006 6:30 AM
MM/dd/yyyy h:mm tt 08/22/2006 6:30 AM
MM/dd/yyyy h:mm tt 08/22/2006 6:30 AM
MM/dd/yyyy HH:mm:ss 08/22/2006 06:30:07
MMMM dd August 22
yyyy'-'MM'-'dd'T'HH':'mm':'ss.fffffffK 2006-08-22T06:30:07.7199222-04:00
yyyy'-'MM'-'dd'T'HH':'mm':'ss.fffffffK 2006-08-22T06:30:07.7199222-04:00
ddd, dd MMM yyyy HH':'mm':'ss 'GMT' Tue, 22 Aug 2006 06:30:07 GMT
ddd, dd MMM yyyy HH':'mm':'ss 'GMT' Tue, 22 Aug 2006 06:30:07 GMT
yyyy'-'MM'-'dd'T'HH':'mm':'ss 2006-08-22T06:30:07
HH:mm 06:30
hh:mm tt 06:30 AM
H:mm 6:30
h:mm tt 6:30 AM
HH:mm:ss 06:30:07
yyyy'-'MM'-'dd HH':'mm':'ss'Z' 2006-08-22 06:30:07Z
dddd, dd MMMM yyyy HH:mm:ss Tuesday, 22 August 2006 06:30:07
yyyy MMMM 2006 August
MM/dd/yyyy 08/22/2006
dddd, dd MMMM yyyy Tuesday, 22 August 2006
dddd, dd MMMM yyyy HH:mm Tuesday, 22 August 2006 06:30
dddd, dd MMMM yyyy hh:mm tt Tuesday, 22 August 2006 06:30 AM
dddd, dd MMMM yyyy H:mm Tuesday, 22 August 2006 6:30
dddd, dd MMMM yyyy h:mm tt Tuesday, 22 August 2006 6:30 AM
dddd, dd MMMM yyyy HH:mm:ss Tuesday, 22 August 2006 06:30:07
MM/dd/yyyy HH:mm 08/22/2006 06:30
MM/dd/yyyy hh:mm tt 08/22/2006 06:30 AM
MM/dd/yyyy H:mm 08/22/2006 6:30
MM/dd/yyyy h:mm tt 08/22/2006 6:30 AM
MM/dd/yyyy HH:mm:ss 08/22/2006 06:30:07
ddd, dd MMM yyyy HH':'mm':'ss 'GMT' Tue, 22 Aug 2006 06:30:07 GMT
yyyy'-'MM'-'dd'T'HH':'mm':'ss 2006-08-22T06:30:07
yyyy'-'MM'-'dd HH':'mm':'ss'Z' 2006-08-22 06:30:07Z
dddd, dd MMMM yyyy HH:mm:ss Tuesday, 22 August 2006 06:30:07

Eg:
DateTime dt = DateTime.Now;
lblAppDate.Text = dt.ToString("dd MMM yyyy hh:mm:s tt");