Long term countdown timer

[RTSLVU]

I am writing a test that will have an event occur six months from starting and they want a countdown to be displayed on the screen.

I have a simple count down timer and looked at some of the examples here but these seem to be geard fo hours and minutes.

I have always found workgin with time displays confusing in LV

I need a count down to display months, days, hours, minutes, and seconds.

[nathand]

Something like this?  This just does a single calculation, without seconds, but it should be obvious how add in seconds and put it in a continuous loop.  It might have some issues around daylight savings time or leap years, I haven't checked thoroughly.

 

Message Edited by nathand on 04-16-2009 02:27 PM

[RTSLVU]

Thank you that should get me going.

I have another question about working with time in LV

When you subtract time it coerces the time and outputs a double

But if you attempt to add time you get broken arrow?

[nathand]

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RTSLVU wrote:

When you subtract time it coerces the time and outputs a double

But if you attempt to add time you get broken arrow?

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What meaning would it have to add April 14th to July 8th?

[RTSLVU]

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nathand wrote:

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RTSLVU wrote:

When you subtract time it coerces the time and outputs a double

But if you attempt to add time you get broken arrow?

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What meaning would it have to add April 14th to July 8th?

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Ok then how would I say add 6 months 4 hours to 1:02PM April 14 2009?

[nathand]

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RTSLVU wrote:

Ok then how would I say add 6 months 4 hours to 1:02PM April 14 2009?

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You would use a VI like this.  I just hacked this together based on my reply to a similar question in another thread, there might be some errors around leap years or daylight savings time or other corner cases that I haven't checked.

It's useful to know that a LabVIEW timestamp is essentially a count of seconds since some specific date (midnight January 4, 1904, if I remember correctly), so you can add seconds, hours and days easily.  Months are harder because they may have variable numbers of days.  In general you can treat a timestamp like any other numeric value.  LabVIEW's Date/Time to Seconds and Seconds to Date/Time functions, used in this VI, do the necessary conversion between a number of seconds and an actual date and time (taking into account leap years, daylight savings time, and local time zone).

Message Edited by nathand on 04-16-2009 04:29 PM

Message Edited by nathand on 04-16-2009 04:33 PM

[nathand]

Sorry about the broken image, I swapped the hours and days on the first upload and just missed the message edit cut-off time to put in the new image, here it is:

 

[Zahkay]

Hello everyone

i am doing a database using excel and labview.

I am able to get the updated date( like the date after 7 days maximum)

but now i want the status automatically

the excel file is like this

date of borrowal   time of borrowal    equipment info   student id    date of returned    status

                                                                                                                          this one i did

if it is already 7 days and the person dont cme to return the equipment, the status should be alarmed

i dont know how to do it. anybody can help please.

i really want help please.

[BowenM]

Are you looking for something like this?

[Zahkay]

hmmmm  exactly. only like if that person didnt returned the equipment, it should be alarmed. .. i dont know how to add that to my VI

like i put in here as in the snapshot

date of borrowal: 24/03/2014

time of borrowal: 1.16

equipment specification:

Studnt ID : 

date of returned : ( i put a delay of 7). 31/03/2014

status: only this one i need help. how to make it automatic like when the date of 31 is reached.

it should be alarmed ( or put a notification)