MOBILE version cuts off calendar

Whole calendar is not showing on iphone/smartphone display.
It cuts off two days of the calendar (my Saturday & Sunday) on the right-hand side.

And when I shrink my desktop browser to the smallest width,
it also cuts off one day of the calendar (my Sunday).

How can I shrink calendar to fit smartphone screens?
PLEASE ADVISE.

https://wordpress.org/plugins/spiffy-calendar/