Are you currently renting? If so you need to plan your moving date around when your tenancy ends. Moving out of your rented property before the end of your term will usually incur payment of rent to the end of the term. This is an expense that you really want to avoid when the money could be better used on the move.
If you are moving into a new area or city, you may also be starting a new job and may have been given a specific start date. If you have a new job to start, it is definitely worth trying to arrange your start date and moving date to be around the same time. Possibly consider taking a week or so from moving into your new house to when you start your new job. This will give you time to unpack and get your new house in order, meaning that you can start your new job without a list of things to do in the new house when you get home at night.
Do you have to be in your new house for the start of school term time? If you have children that are starting school, it would make sense to plan your moving date around the start and end of term time. This makes the summer school holidays the most popular time to move house.
Do you have any important appointments that cannot be moved? Check your diary to make sure that you do not have any important appointments or events on or around your planned moving date. The last thing you need is to give yourself any additional stress, so plan your date for a time that is free in your diary.