To use the script select a timeframe D or W and select the months you are interested in the script settings. You will see all the candles that are part of those months highlighted in the chart.
You can use this script to understand if assets have a cyclical behavior in certain months of the year.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.