There is a 2nd Year Events Calendar Guide for Hero of Leaf Valley now, but it is not that useful yet as it is very much a 'work in progress'. What I have done to improve both the 1st and 2nd Year Events Guides is to add colour coding for the Dates. One reason I write guides actually is rather selfish. I like to use my own guides to organise my own games, especially when I begin a second file. In the old days, when there was more than enough time for these matters, I used to amuse myself by trying to discover the 'earliest possible opportunity' to complete any goal in Harvest Moon.
In any case, colour codes make it easier to use this type of Guide, which essentially is a Calendar Guide for all the Events in Hero of Leaf Valley. Unfortunately, the version that was uploaded Friday has colour coding only for one season. This will be corrected on Monday.
It has been determined now that the weather CAN be changed in HoLV if you reload two days prior to the day you wish to change. If, therefore, you are nearing the last possible opportunity to experience an event that requires good weather, you may wish to make certain that it doesn't rain or snow on the last day when it can be triggered. Remember that any weather is subject to the rules that govern prevailing trends.