Simply add new variable with last reload date information and check it inside your script.
IF $(vLastReload)<date(today()) THEN
..... your script....
LET vLastReload = date(ReloadTime());
Of course document will be called for reloading but nothing will be done on second and afterward calls.
But of course better to use External triggered tasks for these purposes, e.g. Reload after finishing your ETL process.