There is 1440 minutes in a day.
1+4+4=9
There is 86400 seconds in a day.
8+6+4=18
1+8=9
There is 10080 minutes in a week.
1+8=9
There is 31536000 seconds in a year.
3+1+5+3+6=18
1+8=9
There is 525600 minutes in a year.
5+2+5+6=18
1+8=9
It always reduces to 9.
360° 3+6=9
180° 1+8=9
45° 4+5=9
Etc..
https://youtu.be/XiBrT4CoVFk