This scripts calculates the percentage gain in a month (previous 22 trade days).
Firstly, it calculates number of sample days
-> minimum no. of sampling duration = 22
-> maximum no. of sampling duration = increased from 22 until 0day_low > 22_day_high
Example if sampling_duration = 100
Monthly percentage gain = ((Current_Day_High_Price - 0_Day_Low_Price) * 100 / 0_Day_Low_Price) * 22 / sampling_duration