how do i make it detect if ur standing on the surface after a scoreboard timer goes down?

heres what i got so far.. i want it to always run after the scoreboard timer goes down
tick function
execute as @e[scores={timer_one=1}] at @s run say test
scoreboard players remove @e[scores={timer_one=1..}] timer_one 1
execute as @a unless score @s join_check matches 1 run function 404:on_first_join```