I do not understand your question. 372 is over a year's worth, so you obviously do not mind finding a cache on two different January firsts, for example. Thus you already have 372 different days (you say you have 660). If you are looking for the next 372 calendar days, You will complete this by getting your calendar up to three caches per day).
If my answer is not what you are seeking, please advise how 372 different days is different from the 660 you already have.
Filtering for loop 2 shows which dates you need to find a cache to get you to 2 caches per day (70 dates). Below the chart is a summary of the dates, and you can even upload them to your calendar to remind you to go out there and cache.