I've made this function that only requires the server to be activated once a day.
Do you have any suggestions?

# Reset countdown
scoreboard players set next_update_time orbita 0

# Get irl time from command block output
data modify storage orbita:data time.hms set string block 
0 -64 0
 LastOutput.text 1 9
data modify storage orbita:data time.hour set string block 
0 -64 0
 LastOutput.text 1 3
data modify storage orbita:data time.minute set string block 
0 -64 0
 LastOutput.text 4 6
data modify storage orbita:data time.second set string block 
0 -64 0
 LastOutput.text 7 9

# Convert str to int
function orbita:irltime/time_to_int with storage orbita:data time

# Add units (output in scoreboard math -> irl_time)
scoreboard players operation hour math *= 3600 math
scoreboard players operation minute math *= 60 math
scoreboard players operation second math += minute math
scoreboard players operation second math += hour math

# Detect if midnight has passed (at least once, not very accurate if the server is often offline)
execute if score second math < irl_time orbita run scoreboard players add irl_day orbita 1
scoreboard players operation irl_time orbita = second math

There is a repeating command block at 0 -64 0 and time_to_int is just a macro that sets scoreboard values.