Try something like this. You've got to change the sprite, NPC position and something else to better suit your needs:
prontera,150,150,4 script rewards 60,{ mes "Here's your daily reward!"; next; if (#nextrewardtime > gettimetick(2)) { mes "Sorry, it seems you've already got it!"; } else { mes "Take this!"; getitem 512, 1; // Apple #nextrewardtime = gettimetick(2) + 24*60*60; // delay by 1 day } close;}
It parses correctly, but didn't test ingame.