How to use the online timer
Fifteen minutes is a solid length for mindfulness practice: enough to move past the first noisy stretch and settle into observing, without demanding a slot that is hard to defend in a busy week. Shorter sits of five or ten minutes still count, but many people find fifteen is where a session stops feeling like it ended just as it was beginning to work.
The common misunderstanding is that the goal is an empty mind, which puts a lot of people off in the first fortnight. It is closer to noticing a thought arrive, recognising it as a thought rather than as an instruction, and letting it pass without following it into a ten-minute reconstruction of a conversation from Tuesday. A mind that wanders constantly is a mind behaving normally, and each noticing is the repetition being practised.
Comfort is worth attending to, since a knee that has gone numb pulls attention as effectively as any thought. Sit in something you can hold for a quarter of an hour without heroics. A consistent time and place, even a particular chair, builds the habit faster than fifteen minutes squeezed in wherever it fits, and it removes the daily negotiation about whether today is a good day for it.
Common questions
Am I supposed to empty my mind?
No, and that misconception puts a lot of people off early. It is closer to noticing a thought arrive, recognising it as a thought, and letting it pass without following it.
Does it matter where I sit?
Comfort matters, since a numb knee pulls attention as effectively as any thought. A consistent time and place also builds the habit faster than fitting it in wherever there is a gap.