Complex sentence: The foundation stone of the Matrimandir was laid at sunrise on 21st February 1971-the Mother's 93rd birthday-and took 37 years until completion in May 2008.
Split into simpler sentences: The foundation stone of the Matrimandir was laid at sunrise on 21st February 1971-the Mother's 93rd birthday. The structure, took 37 years until completion in May 2008.