Timer Title Number Padding

I have successfully created a timer in my datapack, which displays hours, minutes and seconds on the actionbar. Instead of the minutes & seconds displaying as 05:02 (for example), they show up as 5:2, which is incorrect. You cannot set a score to 05, it just sets it to 5, so I'm not sure how to get it to display with the padded zeroes. This is the code for the title: ["",{"text":"[ "},{"score":{"name":"@s","objective":"hours"},"color":"green"},{"text":":","color":"green"},{"score":{"name":"@s","objective":"minutes"},"color":"green"},{"text":":","color":"green"},{"score":{"name":"@s","objective":"seconds"},"color":"green"},{"text":" ]"}] I can provide the whole datapack at its current state if necessary.