Possible Duplicate:
Are there rules about using “that” to join two clauses?
I see the word "that" used very frequently in newspaper articles. It usually is used after the word said.
Some examples:
He estimated that it was between the hours of 7:30 a.m. and 8 a.m. on Thursday morning that workers realized there was diesel fuel coming up through the ground.
The fire chief said that the fire departments were on the scene at around 8 a.m.
Are either of those "thats" needed? How does one know when it's not needed?