These are all interconnected because of one thing, Francis was born in the wedding.
My Puzzle Pieces:

1-Lois revealed her age in (Season 2 Episode 3 titled "Lois's Birthday") more details to come.

2-Hal reveals their 20th anniversary in (Season 6 Episode 3 titled "Hal Sleepwalks")

3-Franics revealed his 21st birthday in (Season 6 Episode 16 titled "No Motorcycles")

4-Francis is born in the Wedding Day in (Season 2 Episode 25 titled "Flashback")

5-Hal reveals they ALREADY celebrated 22 anniversaries (Season 7 Episode 7 titled "Blackout")

Timeline (Don't concentrate on the ages, just what day the episode happened)