Validity dates of employment

Respected members!

Can someone help me telling which would be the validity date for employment start and end? one date is mentioned in I797, something else mentioned in i129, Now confused which one to reply if a question pops up by VO, i have my appointment scheduled for 19th June’17

In I797 : Validity dates

In I129 : Intended employment start & End date.

Thanks

Jagz