Days vs. Months

Hi guys- I’ve been running into this sort of thing more frequently as of late. When I see an EOC problem that refers to time in months - as in, a currency forward with 3 months to expiration - that signals to me that the time in calculation can be 3/12 or .25. When I see days, as in there are 90 days to expiration, that’s my signal to use 90/365 as time. More than a few times I’ve seen the CFAI pull the opposite - they give you 3 months, then throw 90/365 in there, which ultimately creates problems if you’re looking at questions where decimal places matter (again, case in point would be a currency forward question using USD/JPY, quoting $0.00813 or something). If you’re only keeping 6 digits in your calculator, you’re going to get thrown off in multi-step calculations. Any thoughts on how others on this forum handle days vs. months? Thanks in advance!