You and your crew have to run a LET'S FOOS tournament within the 24h period. When you play in this period, is up to you! Check out here the period translated for your time zone:
And how long you play, is also up to you! Your tournament can last only one round or you play with no end... However, we recommend to arrange a little event for your location and play 1-3 hours. For example: 1 hour pre-eliminiation rounds and then starting the eliminiation round till the final.