You deserve for Yosemite 5 months in advance on the 15th of the month for the entire month up to the 15rh 5 months in advance. So, for example to reserve for April 27, 2018 you had to go online and reserve starting at 7 am Pacific standard time on Dec 15, 2017.
120ish days. Watch for the 15th of the month and be online with 5 browser windows open and ready to click at 6:59:59am pst
I understand reservations can be made on the first of the month for the month 6 months in the future.
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