Referee are asked one question in particular nearly every week: "How long are the halves?" The reason that question gets asked is because few towns seem to play the recommended half lengths consistently.
As an official, it is your duty to know, and govern play using, the proper game lengths as recommended by the CJSA.
The CJSA Spring 2012 NWD Spring Handbook (abbreviated, full version
) lists the game lengths as follows:
U-09 & U-10: 35 min. halves, size 4 ball
U-11 & U-12: 40 min. halves, size 4 ball
U-13 & U-14: 40 min. halves, size 5 ball
U-15 to U-19: 45 min. halves, size 5 ball
The handbook also states the following (my emphasis in bold
): "In certain instances, coaches and game officials may decide to play a shorter game
than recommended. This is acceptable provided it is mutually agreed upon and the game consists of two equal halves."
You should always use the half lengths as indicated above, regardless of coaches discussing what they have played previously, or always play.