execute unless score @s hours matches 1.. unless score @s minutes matches 1.. run tellraw @s [{"score":{"name":"@s","objective":"seconds"}},{"text":"s"}]

execute unless score @s hours matches 1.. if score @s minutes matches 1.. if score @s seconds matches 0..9 run tellraw @s [{"score":{"name":"@s","objective":"minutes"}},{"text":":0"},{"score":{"name":"@s","objective":"seconds"}}]

execute unless score @s hours matches 1.. if score @s minutes matches 1.. unless score @s seconds matches 0..9 run tellraw @s [{"score":{"name":"@s","objective":"minutes"}},{"text":":"},{"score":{"name":"@s","objective":"seconds"}}]

execute if score @s hours matches 1.. if score @s minutes matches 0..9 if score @s seconds matches 0..9 run tellraw @s [{"score":{"name":"@s","objective":"hours"}},{"text":":0"},{"score":{"name":"@s","objective":"minutes"}},{"text":":0"},{"score":{"name":"@s","objective":"seconds"}}]

execute if score @s hours matches 1.. if score @s minutes matches 0..9 unless score @s seconds matches 0..9 run tellraw @s [{"score":{"name":"@s","objective":"hours"}},{"text":":0"},{"score":{"name":"@s","objective":"minutes"}},{"text":":"},{"score":{"name":"@s","objective":"seconds"}}]

execute if score @s hours matches 1.. unless score @s minutes matches 0..9 if score @s seconds matches 0..9 run tellraw @s [{"score":{"name":"@s","objective":"hours"}},{"text":":"},{"score":{"name":"@s","objective":"minutes"}},{"text":":0"},{"score":{"name":"@s","objective":"seconds"}}]

execute if score @s hours matches 1.. unless score @s minutes matches 0..9 unless score @s seconds matches 0..9 run tellraw @s [{"score":{"name":"@s","objective":"hours"}},{"text":":"},{"score":{"name":"@s","objective":"minutes"}},{"text":":"},{"score":{"name":"@s","objective":"seconds"}}]