Once out of every two weeks of the year would be how may days through out the year

26 most years; 27 some years

Step-by-step explanation:

1 day out of 14 is 1/14 of the number of days in a year.

The number of days in a year depends on the year or years you're talking about. In all cases, there are not an integer number of weeks in a year, so days are left over. 365/14 = 26 1/14.

For example, if you're concerned with every other Monday, most years, there will be 26 of them, but every few years there will be 27. Over a period of 800 years, there will be exactly 71 years with 27 days of interest instead of 26. 800 is not divisible by 71, so the spacing will be uneven.