There is no time limit, even in Australia last time I looked.
I have seen it stated that if a baby survives a botched abortion [US] and is living, breathing it can still be legally killed. Just recently an amendment to protect that living baby was rejected, I forget the jurisdiction.
Your stated position is that the mother's rights are absolute. When does killing a baby cease to be legal in your eyes? Why isn't it legal in the first trimester after birth?