Okla. Stat. tit. 25, § 25-23: Time

The word "year" means a calendar year, and "month," a calendar

month. Fractions of a year are to be computed by the number of

months, thus: half a year is six (6) months. Fractions of a day are

to be disregarded in computations which include more than one (1)

day, and involve no question of priority.