Time comparison (CompareTo) accuracy of datetime

If the current time is July 19, 2007 13:56 47 seconds
Convert.todatetime ("07/07/19"). CompareTo (DateTime.Now) The value returned at this time is "-1"
Result: Convert.todatetime ("07/07/19") represents a time less than DateTime.Now
Reason
The time represented by Convert.todatetime ("07/07/19") is: 2007-7-19 0:00:00
DateTime.Now the time indicated: 2007-7-19 13:56:47

If we now only do the exact "day" time comparison, then the two time to the same precision.
Method
Convert.todatetime ("07/07/19"). CompareTo (Convert.todatetime (DateTime.Now.ToString ("Yy/mm/dd")) The value returned at this time is "0"
Result: two times equal

Conclusion
When comparing two times in datetime, pay attention to the accuracy of two times.FeedBack:1059370 #1楼 2007-07-19 14:41 black0[unregistered users] Oh, so it is.
Reply Reference #2楼 2007-08-02 10:57 brooklet[unregistered user] Convert.todatetime ("07/07/19"). CompareTo (DateTime.Now.Date)
Reply reference #3楼 [landlord] 2007-08-02 22:57 pcjim @brooklet
It is also a good way to get the date part of the current time with date, thanks for pointing out.

Reply Reference View #4楼 2008-01-09 11:20 qwq[unregistered user] int v = dateTimePicker1.Value.CompareTo (datetimepicker2.value);

if (!) ( DateTimePicker1.Value.Equals (Datetimepicker2.value))
{
if (V > 0)
{
MessageBox.Show ("Delivery time can not advance with the pick-up time ...") ");
return false;
}
}



I would like to ask you to express your views.
(The problem that arises is the time and time error)
Reply reference #5楼 [landlord] 2008-01-31 06:36 pcjim @qwq
Datetimepicker1.value {2008/01/31 5:30:42} System.DateTime
Date {2008/01/31 0:00:00} System.DateTime
Day int
DayOfWeek Thursday System.dayofweek
dayofyear int
Hour 5 int
Kind Local System.datetimekind
Millisecond 296 int
Minute int
Month 1 int
Second int
Ticks 633373542422968750 Long
TimeOfDay {05:30:42.2968750} system.timespan
Year 2008 INT

Datetimepicker2.value {2008/01/31 5:30:42} System.DateTime
Date {2008/01/31 0:00:00} System.DateTime
Day int
DayOfWeek Thursday System.dayofweek
dayofyear int
Hour 5 int
Kind Local System.datetimekind
Millisecond int
Minute int
Month 1 int
Second int
Ticks 633373542422500000 Long
TimeOfDay {05:30:42.2500000} system.timespan
Year 2008 INT

The above is the value of the datetimepicker1.value and datetimepicker2.value monitored after the breakpoint is added, and the surface {2008/01/31 5:30:42} is consistent with {2008/01/31 5:30:42}. But millisecond:296 > 250, this may be the cause of "time and error".
Modified as follows:
int v = dateTimePicker1.Value.Date.CompareTo (dateTimePicker2.Value.Date);
if (!) ( DateTimePicker1.Value.Date.Equals (dateTimePicker2.Value.Date))
{
if (V > 0)
{
MessageBox.Show ("Delivery time can not advance with the pick-up time ...") ");
return false;
}
}