You can store the time and/or date in a text file through the STORE statement. Then you can have a small load script being run every minute, five minute, 10 minute, hour or whatever kind of resolution you need to check if the time in the text file has arrived or been passed and then run the rest of it's load script or exit (and wait for the next check interval).
// Load script that controls when a script should start:
vTimeToStart = Date(Today() + 1/24); // in an hour
TIMETOSTART:
LOAD * INLINE [
TimeToStart
$(vTimeToStart)
];
STORE TIMETOSTART INTO LIB://myScriptFolder/TimeToStart.txt (txt);