Transferring your Lifetime ISA takes you 5-minutes to initiate, but it will take us longer behind the scenes to arrange for the funds to be moved. We ask for 2-6 weeks, but it's very rare it would take the full 6-weeks and can be as short as 5-days.
A question we often get from people considering making a transfer, is whether they'll be earning interest in those 2-6 weeks.
You'll earn interest with the old provider up until the day they transfer the funds, and begin earning interest with the new provider once the money lands in your Lifetime ISA. If that happens overnight, there could possibly be one day that you're not earning interest, but it certainly wouldn't be for the full period!