variables:
    {timer.%player%} = false
command /timer:
    trigger:
        set {timer.%player%} to true
        set {_start} to now
        display board named "StopWatch" to player
        while {timer.%player%} is true:
            set {_diff} to difference between now and {_start}
            make score of "Time" in board of player to {_diff}
            wait 1 second
command /timerstop:
    trigger:
        set {timer.%player%} to false