Cameras sync. Determine frames timestamp

My setup JetPack 4.6, LI 6x cameras imx577 on adapter with FPGA sync.
After accuireFrame, getTime of each frame is different >=1ms.
Frames were triggered at one time by FPGA chip.
How to determine real (closer to real) timestamp when frames was made?
What is the getTime? It is before ISP or after ISP?

From here: Argus Timestamp Domain - #13 by j2innet

Argus::ICaptureMetadata::getSensorTimestamp is answer?

Yes, you can also reference to below API.

It works. Thanks.

Jetson time has pps sync from gps UBLOX module.

Now i am using getSensorEofTimestampTsc().
As i see it is MONOTONIC_RAW clock and does not depend on system time and gps sync.
Tell me please how far MONOTONIC_RAW clock can runaway per day?

Please help to open a new topic for your another issue. Thanks