I have never been good at in game time management, but I'd love to get better. Anyone have any good tips on how you do it. Is there an online app or something where you can set a clock and tick away every turn and advance the clock when the party spends time searching. So I can more accurately be able to gage, when they should be hungry or tired?

I was thinking of taking an old broken face clock and just manually moving the arms. I'm open to suggestions. Thanks.

In the default/base setting of Forgotten Realms weeks are ten days long (called a ten-day) and there are three weeks in a month and 12 months in a year for a year of 365 days. You will notice that this links up pretty well with our own calendar. So if you are trying to track seasonal change and such then its easy enough to go from winter to spring to summer to fall. There are a number of holidays throughout the year, and most diety have a holy day or two scattered about as well. 

From there we have three scales of time, minutes, hours, and days. 
The PHB recommends a scale of about 1 minute to check for traps and 10 minutes to search a room for loot. 
When traveling shortly to medium distances an hour is best to use, the example listed in the PHB is 15 miles in 4 hours or roughly 3.75 miles an hour. 
For longer journies like from city to city break the time down into days.

What matters most is tracking the player's speed and pace. The players handbook (PHB) has a chart breaking down the distance traveled by players depending on the scale of time used, and the pace at which the players are traveling, for example, a group traveling at a fast pace would cover about 30 miles in a day, while one traveling at a slow pace would hit about 18. Things like terrain, encounters, and events can alter this.

I would recommend you get a calendar, or a calendar app, mark the real world equivalent of when your game started and after sessions and downtime update your current day on that. Since the base setting uses lunar months (30 days across three weeks that are 10 days long) a calendar that has the moon cycle on it will help with the conversion from earth month to Toril (Forgotten Realms) month. 

More information on time and travel is in both the Players Handbook (PHB) and the Dungeon Masters Guide (DMG) and calendar information including holidays are in the Sword Coast Adventures Guide (SCAG).
Good Luck, Have Fun

http://theangrygm.com/hacking-time-in-dnd/ & http://theangrygm.com/exploration-rules/

Two really great posts on time pool that really helped my game management.  

I also created tracking sheets that were basically a large spreadsheet filled with "0" in blocks of ten with labels.  

I honestly think the dice pool works best for in dungeon type time. When I reach over the screen and drop a die in the mug, everyone knows what is happening.  I put a X in a circle on my tack sheet when I cycle the mug

For spells, I write down when cast and then I know how long it lasts.  My players tend to do a fair amount of 1 or 8 hour spells and then helps them know how long is left and that they got a fair duration.  

Also, with FR ten day work, I dropped the blank calendar idea. Now, I use a simple notebook journal that just logs what they did by day.  Sometimes it's a bit on the dungeon, who met, treasure, but it can also be one line ("10 to 14 Ches -- travel to Yartar").