The academic calendar at any institution is drawn up by the institution itself. While there may be some differences between the academic calendars of Christian colleges and secular colleges, it is hard to give general answers as to what those differences would be across the board.
Typically, both secular and Christian colleges include breaks or days-off for all the major holidays, fall and spring breaks, and Christmas and summer breaks. Many colleges, Christian and secular, offer a sort of summer semester if students need or want to get credits done during the summer. Some colleges offer class-terms during winter, that may result in a later start for spring classes.
If a Christian college offers options for mission trips or ministry opportunities, that may affect the calendar some, marking another difference that may be present between Christian and secular college calendars. That said, there are bound to be small differences in the calendar year between every college, Christian and secular alike.
Students should always look over a copy of the academic calendar of their college or desired college ahead of time. Usually, a copy of the academic calendar is posted on the official website of the college, but students can also ask for a copy from faculty members, academic advisors, or the admissions department.