We need to stay back/behind until late in the night to finish up all the tasks that needs to be completed.
We need to stay behind until late into the night to complete all the work that needs to be completed and to prepare all the ingredients for the next day or weeks.
We used this freezer for storing meat.
We need to come in a little bit earlier before the opening time.
We need to leave a little later than the closing time.
Did I phrase the above sentences correctly? Please advise.