As far as I can see, you don’t store the view count with sufficient granularity to do what you want to do. You can’t distinguish when the view occurred, so you have no way of knowing how many of the views happened within the last 24 hours (or any other period).
It doesn’t provide enough information for you to query by period.
The simplest approach would be to create a separate table (say post_views) with a single entry for each view, recording the post ID and the view timestamp. That could get very large very quickly though.
To minimise the overhead, you could possibly use a table tracking views per day. The table would need to record the post ID, the date (could just be the integer portion of a Unix timestamp) and the view count for that day. When a page was viewed, you would check to see if a view count record exists for the relevant post and current day. If not, you would create a new record, initialising the view count to 1. Otherwise, you would increment the view count.
It seems like a lot of work, but I can’t think of a simpler way of achieving what you’re trying to do.