See explanation below.
Navigate to General ledger > Ledger setup > Date intervals.
Click New.
In the Date Interval Code field, type a code such as CurrMth PY.
In the Description field, type a description such as Current Month Previous Year.
In the Interval Start section, select Month in the From date period type field.
In the From date start/end, select Start.
In the From date +/- field, type -1 for -1 year (previous year).
In the From date adjustment unit field, select Year.
In the Interval End section, select Month in the From date period type field.
In the From date start/end, select End.
Click Save to save the date interval.
Reference:
https://docs.microsoft.com/en-us/learn/modules/create-fiscal-calendars-years-periods-dyn365-finance/7-date-inte