Calendars and Miscellaneous ⇒ calendar with consistent height

[mlvezie]

I'm using calendar.sty to create a very full calendar with no empty days, but a variable number of entries per day. The example has some days with entries and blank days with \vspace{2.5cm}. My problem is that since all my days have entries, and the \vspace{2.5cm} adds to the end of the entry, I can't use \vspace. I want to make all the days have a consistent height, but without some command to ensure each row has a fixed height, each row is as high as the fullest cell.