Plan a job start date and notice period.
A start date is the sum of three intervals that are easy to underestimate: the days before you formally accept and resign, the notice period itself, and any break you want in between. Unused leave can shorten notice where the employer agrees to it, and because leave is counted in working days while notice runs in calendar days, five leave days offsets seven calendar days of notice.
Start date from notice and leave
Effective notice days = notice weeks x 7 - unused leave x 7/5; days until last day = acceptance days + effective notice; days until start = that + break
Notice periods, leave entitlement and the treatment of unused leave are governed by your employment contract and local law. Confirm the position with your employer or an employment adviser before committing to a date.
Only with the employer's agreement. Many contracts allow it and some require leave to be taken during notice, but others insist on paying it out instead. Confirm before promising a start date that depends on it.
One to two weeks is common and usually beneficial — starting a demanding role immediately after finishing another is where early burnout often begins. Longer breaks are fine but need agreeing with the new employer at offer stage.
Ask your current employer whether notice can be shortened by agreement, which is often possible when a handover is straightforward. Simply leaving early without agreement can breach the contract.