Anon clocked my thoughts…

i is 9th letter of alphabet

9 oclock coincides with 45 minutes on a clock

Is marker [i] related to [45] delta?

45 is potus, i is potus?

Or maybe…

[0] = 12 = L?

[5] = 1 = A

[10] = 2 = B

[15] = 3 = C

[20] = 4 = D

[25] = 5 = E

[30] = 6 = F

[35] = 7 = G

[40] = 8 = H

[45] = 9 = I

[50] = 10 = J

[55] = 11 = K

[60] = 12 = L?

(Could continue through mnopqrstuvwxyz or 130, with R being [90])

So… marker [30] posted yesterday is also marker [F]?