When a domain is transferred between registrars, one year is added to the expiration date for the domain. The expiration date itself does not change or "start over." 

If your domain name is within the 45-day registry auto-renewal time frame, an additional year will not be added to the domain expiration.  We recommend transferring before renewal, or waiting 45 days after renewal to make a transfer.  Anything during the first 45 days will not have an additional year added to the expiration date for the domain.

Note: Domains that are not yet 60-days old are not transferable between registrars. This is a registry restriction, not a regulation instituted by VodaHost.