BugFix: Handle days when dining hall isn't open for ordinary hours

[tremblay]

Currently, the app crashes if the first day isn't for a few days (i.e. if the dHall is closed today). Furthermore, if the first meal of the day is Dinner (like on the first day), the menu won't display for any meal during the day. This MIGHT be something to put off until we re-work the back-end, since I expect to give the dHall staff greater control over this by giving them an interface to post the hours and such.

[tremblay]

App no longer crashes, but there is an issue with the fix, which causes the app to never load any data if it opens to a day without a menu