changing corner reference calendars..Help!

[MJ]

I need to change the reference calendars in the upper right hand corner of
the calendar when printing the calendar out.

Currently when printing the monthly calendar the main calendar and the first
of the two small reference calendars in the upper right hand corner match,
the second of reference calendars is the next month.

Is there a way to change the two small reference calendars so that one is as
the previous month and the second as the following month?

Thank you
MJ