Why wont this script change the string value?

I want this to change the string value to 2nd but it won't work. Script:

while true do
    wait(0.1)
if game.ServerStorage.ClockValues.minutes.Value == 0 and game.ServerStorage.ClockValues.seconds.Value == 0 and game.ServerStorage.ClockValues.per == '1st' then
        game.ServerStorage.ClockValues.per = '2nd'
end
end