Hello!
Please, help me to understand the mathematical logic behind the money market yield.
Here is the equation:
money market yield = [360 x r BD] / [360  (t x rBD)]
where rBD is the band discount rate; t  days till maturity.
For example:
r_{MM} = (360)(0.05)/[360 − (120)(0.05)] = 0.0508
Here is how I started interpreting the math (but stumbled):

in the numerator we have 360 x bank discount rate = 360 x 0.05 = 18; this seems to give the number of periods within a year, during which 0.05 could be earned; is that so?

(120)(0.05) = 16 this also gives the number of periods, but what these periods mean?

[360 − (120)(0.05)] = 360  16 = 354 what happens here?

finally 18 / 354 = 0.0508 I guess I will be able to understand what happens here if I understand three previous ones.
Thank you very much!