Far more disruption than you think, because that would result in daylight at midnight and nighttime at noon for a good chunk of the year. Instead, I suggest permanently extending February to 29 days instead, with a 30th day in leap years. This would limit the disruption to a single month (March), and only by an offset of one day. I never understood what February did wrong to be disrespected with such a short month anyway. Instead, February would be equal in length to April most of the time, and every four years (at least within our lifetimes *cough2100cough*) it would get to gloat over being longer than April.