I think it's probably after a year.. Then people seem to think you should be preparing to wean your child, from my experience anyway.
I bf ds1 til 18 months and he self weaned having lost interest slowly.. and he began making use of emotional comfort from hugs etc and language and transitional objects..
Dd2 however is now 4 and still bf..
She has special needs and can't quite cope with the idea that bf is not available for comfort although does not require it for nutrition of course anymore.
I never set out to bf her this long - to be such an extended breastfeeder, but it still feels right for us and it is a wonderful way to soothe her especially when we're in hospital situations.
I sometimes feel uncomfortable about how old she is but I've never had any negative comments from anyone although it's not something I do outside home or familiar places or in stressful situations these days.. I don't want to invite any negative comments, our lives are hard enough , I but may have just set myself up for some comments here.. I hope not though.
I remember reading somewhere about b/f babies having a higher IQ than non-b/f babies and this has encouraged me to continue as dd needs all the brainpower she can get..
Also, I've frequently been on paediatric wards in hospital and been so relieved that I still have breastfeeding to soothe and comfort her.
On those occasions, it feels like magic.. I'm so grateful to be able to offer that..