'Appointed Time' in the Bible

and My covenant I establish with Isaac, whom Sarah doth bear to thee at this appointed time in the next year;'

And Jehovah saith unto Abraham, 'Why is this? Sarah hath laughed, saying, Is it true really -- I bear -- and I am aged? Is any thing too wonderful for Jehovah? at the appointed time I return unto thee, about the time of life, and Sarah hath a son.'

and Sarah conceiveth, and beareth a son to Abraham, to his old age, at the appointed time that God hath spoken of with him;