When did it go into effect at 455 a week

Federal law went into effect I believe 2004. Most states had to go back and change their state laws after that. Since in many cases it was a lot more than some state salary laws.

This normally effects overtime laws. This came off a states web site that showed it was required to change its laws in 2004 when the federal laws changed, so not sure when it took effect but it appears sometime during 2004.

Many companies do not realise that to be on salary there is a required amount, often the state law is higher than the federal.