The length of the year changes--off the top of my head I'm not sure if it gets a day longer or a day shorter. That won't matter from an ecological perspective but the inhabitants might care about the broken calendar.

Also, interplanetary spaceflight is severely curtailed. Until we build a supercatapault on the moon there will be no manned missions beyond the moon and the only way to rendezvous with another planet will involve really brutal aerobraking--twice that of the Galileo probe's plunge into Jupiter. (Which burned away a quarter of the total weight of the probe.)

Edit: I got it a bit wrong. I originally said the length of the year changes by a day--now I realize that while the number of calendar days changes by 1 the length of the year remains the same--the length of the day also changes. Neither effect will matter ecologically but the inhabitants very well might care.

Also, interplanetary spaceflight is severely curtailed. Until we build a supercatapault on the moon there will be no manned missions beyond the moon and the only way to rendezvous with another planet will involve really brutal aerobraking--twice that of the Galileo probe's plunge into Jupiter. (Which burned away a quarter of the total weight of the probe.)