When adding days to dates, or subtracting days from dates, you can use only an integer number of days (a whole number); you cannot add or subtract non-integer numbers of days (1/2 days, 3.6 days, and so on).
Wakati kuongeza siku kwa tarehe, au subtracting siku kutoka tarehe, unaweza kutumia tu integer idadi ya siku (idadi nzima); huwezi kuongeza au Ondoa idadi zisizo integer ya siku (siku 1/2, siku 3.6, na kadhalika).