Getting data aquisition time of the psdata file

Hello together
I use python for data analyse. The conversion of the measured files is psata -> mat.

The comand line version for converting psdata files into matlab format, looks like shown below
p = subprocess.Popen(['picoscope', '/c', path_file_dest, '/f', 'mat', '/q /b 1'], stdout=subprocess.PIPE)

The information which I also need is the displayed aquisition time from the picoscope software. This time differs from the time of the file date shown from the operating system.

The command "sci.io.whosmat(MATFILE)" shows as result e.g.
[('Tstart', (1, 1), 'double'), ('Tinterval', (1, 1), 'double'), ('ExtraSamples', (1, 1), 'double'), ('RequestedLength', (1, 1), 'double'), ('Length', (1, 1), 'double'), ('A', (21736714, 1), 'double'), ('B', (21736714, 1), 'double'), ('Version', (11,), 'char')]

The 'Tstart' doesn't have any value.

Are there any possibilities for getting this information

Regards
Alfons