Hi Manish,
Default Time Frames
Daily: Today, Yesterday
Weekly: Current Week, Previous Week
Monthly: Current Month, Previous Month
Yearly: Current Year, Previous Year
Custom Time Frames
Custom Day: Any day in the last 30 days
Custom Week: Any week in the last year
Custom Month: Any month in the last two years
So the Previous Month and Last 30 days are different.
Previous based on calendar , vs past 30 days
same goes to "Yesterday" and "Last 24 hours"
Thanks
Yanna