It strongly depends on the company. Many companies use vacation time as a perk strictly for seniority, and are inflexible about changing it; or if you do get a break, you forego further increases until your seniority has "caught up".
It's pretty stupid, particularly since it's a fairly strong disincentive to relocate: precisely after you've moved away from friends and family, they give you less time to visit them. It was one of the biggest reasons I never moved to CA when I had the offer, H-1B, etc.
