Labview ver 6.02

[AndyB]

Is there a problem with Numeric control when set to time format and trying to set to zero whilst the date is in Day light saving time. Have tried this before BST and there is no problem with the numeric control the default vale is 0:00:00. When BST is set then the default value is 1:00:00 and can not be set below low this value.
Is this a bug in LV if so whats the work around as all my time VI are US.

[Aaron Marks]

Not sure I understand the question? You should not be able to set a value below 01:00:00 if you have the time format set to AM/PM. This, of course being because the clock starts at 12:00:00. If you want to be able to set 00:00:00 you have to have the clock in 24 Hour format. I'm not sure what day light savings time has to do with it or what BST refers to.

[Matt_K]

When you refer to BST, I assume you are talking about British Summer Time. I think the problem you are experiencing is a result of how we handle time zones and their numeric representation in general. In LabVIEW, a zero in numeric format will not correspond to 0:00:00 but rather the amount of time you differ from GMT on 1/1/1904. Here in the Central US we're GMT-6 so my 0 base is 18:00:00 12/31/1903. When you try and enter a 0:00:00 you are in negative time (arbitrarily set) so LabVIEW sets it to something else. If you enter 0:00:00 4/4/02 it will show up as 0:00:00 since you are in positive time.

You would normally experience this problem year round but if you live in Britain you happen to be in one of the few places in the world where you are GMT +-0. If yo
u just type in a 0 it will default to 0:00:00 part of the year. Now that you switched to BST you are no longer exactly at GMT.

Please let me know if I misunderstood the problem. If this is the case, please try and include as much additional information as possible in your comment.

Matt Kisler
Applications Engineer
National Instruments