When the City converted to citywide permit parking, the new rules went into effect on January 4, 2010. For new permit holders in Zones 1, 2 or 3 (exp. Jan, Feb, March), T&P issued stickers that were good for 13, 14 or 15 months instead of the usual 12. From now on, though, if you buy a new car or move into Somerville, you have to pay the full price for a sticker that's good for a partial year. That's the way it was before the switch and the way it will be going forward.