Counting the minutes till dusk so that you could gladly break your fast is not something useful or beneficial at all. Maximize your productivity. Or at least make something worthwhile. I'm pretty sure, there is always something that you could do.
Ps : Damn. My plan to meet the girl from yesterday got ruined cause I'm stuck in a traffic jam for almost 3 hours. And I only berbuka with a bottle of mineral water in the car. Sigh. I hope it won't happen again tomorrow.