Convert TAI time (in seconds) to UTC (in seconds, LabVIEW format)

[Simon_Stenfeldt]

I need to convert TAI time to LabVIEW time.

Basically I have the number of seconds since TAI epoch and need to convert that to the number of seconds since LabVIEW epoch. This value can then be converted to a UTC timestamp using standard LabVIEW functions.

[A.Rohde]

Hi Simon

Have you solved your problem?

The difference in TAI and UTC is that TAI doesn't account for leap seconds. Due to that fact TAI is currently ahead of UTC by 34 seconds. Isn't it enough for your application just to subtract the 34seconds? 

If not I may have misunderstood your question, then could you try to explain it again in a bit more details?

Best regards,

Anders Rohde

Application Engineer

National Instruments, DK

[Simon_Stenfeldt]

Hi Anders

Thanks for your reply. I dont need the UTC time, I need the Labview time (number of seconds since 1/1 1904).

From a GPS system I can extract the TAI time (seconds since TAI epoch) - lets call this value x. I need to convert this to a labview time stamp (decimal point number, seconds since 1/1 1904) (lets call this y).

The conversion will be a constant (lets call this c) and also the number of leap seconds (lets call this n).

The formulae would be:

y = x + n + c

curently n is 34 seconds.

What I need to know is the constat c.

[A.Rohde]

Hi Simon

Have you looked at the following community example about converting between local time (LabVIEW time) and UTC time?

https://decibel.ni.com/content/docs/DOC-11514

Based on that I have created a example program to you that should solve your problem in the following way:

TAI Time -> Convert to UTC time -> Convert to LabVIEW time.

The example is attached to this post

Best Regards,

Anders Rohde

Applications Engineer

National Instruments Denmark