I appreciate there are many posts around this topic already and I've read through a lot of them. Thank you to everyone who has already posted their thoughts and feelings on this topic and also for taking the time to read yet another take.
Just over a year ago I moved up from a Senior roll into a Scrum Master position in an established team previously supported by a contract Scrum Master.
He ran the sprint planning and estimation using the following scale:
1 point = 1 hour
3 points = a morning or an afternoon
5 points = a day