From today’s Gospel in the Novus Ordo Missae:
 Jesus saith to her: Go, call thy husband, and come hither.  The woman answered, and said: I have no husband. Jesus said to her: Thou hast said well, I have no husband:  For thou hast had five husbands: and he whom thou now hast, is not thy husband. This thou hast said truly. ~St. John’s Gospel 4:16-18
The five husbands represent five marriage-covenants, five dispensations between God and mankind. Five ages of the world preceded the coming of the Messiah:
1.) Adam to Noah
2.) Noah to Abraham
3.) Abraham to David
4.) David to the Exile
5.) The Exile to Christ
Each of these dispensations passed away; the terms of the union were fleeting; a new union superseded the old. Each time, mankind turned away from God, and God repudiated the union. But the Messiah is the Bridegroom of a new and everlasting covenant.
The Messiah arrives at the well at the sixth hour of the day (i.e. noon) because He commences the sixth age of the world. Noon divides the day into A.M. and P.M., and Christ divides human history into B.C. and A.D.