Add extra exception handing to parent record type
Add extra exception handing to parent record type

- Move call to datetime function to its own try...except block as it needs
  differetnt handling to the int call raising a ValueError. In the former
  case it is likely to be a timestamp out of range (possibly caused by
  Grid Engine oddness).

apel/apel,tofu-rocketry/apel,stfc/apel,stfc/apel,apel/apel,tofu-rocketry/apel