If you buy into the Maggie's Farm approach to "Balanced Fitness for Life", the issue of scheduling comes up (altho not if you do Crossfit, which has a good stew of everything, varying every day, so most Crossfitters go 4-6 days/wk).
Our approach (with expert consultation) is to do your calisthenics classes or calisthenic routines on the day after a weights and powerlifting day. That sort-of counts as an "active recovery" day. If you do a tough calisthenic athletic cross-training hour the day before lifting, most people over 35 will not be at 100% for their weights day.
So that's 4 days right there, assuming you do weight sequences twice weekly. On days before weights, there is no problem with cardio like HIIT or even "long, slow" as a recovery day. (I do "long slow" - elliptical, stairmaster, treadmill - on Sunday mornings before church if there is no big hike planned. Day of rest.) Important to move with intention every day to remain functional.
Every three months it's not a bad idea to take a complete week off from a tough exercise regimen. A week off means away from the gym, and just doing recreational things like hiking, jogging, and swimming. That's a "recovery week." Just bear in mind that, after ten days without hard exercise, fitness measurably declines after age 40.
