Sure you can, just not by months, you would need to use weeks instead to retain integer values. A half year would be 26 weeks and a quarter year would just be 13 weeks. Of course this fails if you wish to divide further, but at that point you could just say 2 months and people would know for certain you are saying 8 weeks.
The issue is that 13 is not divisible by anything, so we can’t split the year by halves or quarters like we do now.
Sure you can, just not by months, you would need to use weeks instead to retain integer values. A half year would be 26 weeks and a quarter year would just be 13 weeks. Of course this fails if you wish to divide further, but at that point you could just say 2 months and people would know for certain you are saying 8 weeks.
Well, pregnancies are measured in weeks, so not that big of a leap.