Nuimatalolo became an assistant at Navy in 1995.
He was an assistant at UNLV from 1999 until 2002 when he returned to Navy. He has been at Navy sense then.
If he gets credit for his initial four years then he should have his 20 years in this year. If not credited with his first four years (prior to going to UNLV), then 2022 is when he has his 20 years.
I suspect that since it's the government, he won't be penalized for the employment gap.