We started 10 years ago, but as we got older, so did DGS. We stuck to our guns one day a week, with the odd evening (other GPs do that mostly as they have a spare bedroom and are 10 years younger).
But now he is older, it is more about feeding and hosting a friend or delivering/collecting from various friends. I do not think I could manage a toddler any more.
Recently they have been ducking out for last minute holidays meaning we take up the slack, and DH gets a bit cross. While we do have sympathy for the sheer cost, parents are now getting more "free" hours for younger children, so perhaps it will ease a bit?
You really do have to have a plan of what you can cope with and stick to it, saying sorry you are booked. Do set limits though if you cannot cope with long days (mine can be 12 hours in the holidays). It helps if you are in contact with the other GPs to sort out what suits you both
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