i need help with the period

The period  is  12

The curve  starts  at   62  and decreases  untl  it bottoms out  at  38  at 3 hours....this is (1/4) of the period

Then ii rises  back to  62   agai at  6  hours.......this is 1/2   of the period

Then.....it  rises  to a max  of 86  at 9  hours.....this is  3/4 of  the period

Then  it will fall to 62   [not shown ]  at 12 hours