1) Go to the Service Desk Server, open command prompt window and run:
pdm_options_mgr -s EXPANDER_FORMAT -v dd/mm/yyyy -a pdm_option.inst
pdm_options_mgr -t EXPANDER_FORMAT -v dd/mm/yyyy -a pdm_option.inst
2) Restart Service Desk Services
3) From now on the format will be: dd/mm/yyyy in the display and log entries. The old registries will not change format.