There are several options.
A rough way (which however doesn't work if you are in Windows, or if you use a queuing system to launch ATK) is to issue the ATK command wrapped in shell "date" statements, that is
date ; atk myinputfile.py > logfile.log ; date
However, this will not print the date to the logfile (logfile.log), so we're much better off using Python (as usually is the case
).
A quite fancy method, which also can calculate how long time the calculation took, is discussed
in the manual.
The most convenient solution is, however, probably to just add these lines in the beginning and end of the input script:
import datetime
print "Calculation started:", datetime.datetime.now().replace(microsecond=0)
...
# ... original script ...
...
print "Calculation ended:", datetime.datetime.now().replace(microsecond=0)