If you are using win32api then use win32api.GetSystemTime and win32api.SetSystemTime:
system_time = win32api.GetSystemTime()
# do stuff here
import subprocess
filepath="D:/path/to/batch/myBatch.bat"
p = subprocess.Popen(filepath, shell=True, stdout = subprocess.PIPE)
stdout, stderr = p.communicate()
#p.returncode is 0 if success
# more stuff
win32api.SetSystemTime(*system_time)