Hi win2,
1) You can directly use it. It gives you a relative timecounter like the standard millisecond timer functions.
2) You should NOT put your own functions into LabView's 'private' function libraries! There's a folder named 'user.lib' for just this purpose!
Best regards,
GerdW

using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019