Turns out the the solution was a lot simpler that I thought
I used the following example (seen this over at Openwrt forums) 00 07 * * Mon,Tue,Wed,Thu,Fri wifi down 10 07 * * Mon,Tue,Wed,Thu,Fri wifi up
00 07 * * Mon,Tue,Wed,Thu,Fri wifi down
10 07 * * Mon,Tue,Wed,Thu,Fri wifi up
seems to work exactly the way I want.