Is there a break in period? March 09, 2018 11:42 Follow We do suggest that you give your Simba at least 30 nights to ‘bed in’ – any new mattress can feel a bit different at first. Related articles My mattress arrived, how do I set it up? I've unpacked it, how long until bedtime? What base should I put my Simba on? Where do I apply my discount code? Can I use the mattress on the floor? Comments 0 comments Article is closed for comments.