Its been a long time since I actually played Planco, but I believe I have the correct numbers here:
1 month in Planco is approximately 12-14 minutes, with 8 months in a year (skipping November 1st - March 1st) a single year is approx 95-110mins (thats with default settings) also the sun sets and rises once per month
You can change the hours per day your park is open and the cycle will skip over the hours your park is closed (so if your park is open 24hours a day then each month will be longer, but if you have your park open for less than 24hours then months will go by faster)
Compared to RCT3 which was aprox 7min per month (50-55m per year) and RCTClassic at 5-6min per month (and 35-45m per year)
Not sure if Plazoo will be the same as Planco or not though