The coordinates for this date are:
0.17946799469778313, 0.8615360124576236
Coordinates
Boston -- The coordinates are in a wooded area to the southeast of Woonsocket, RI.
Chicago -- The coordinates are in a farm field to the northeast of Bourbonnais, IL
Plans
User:xkcd will attempt to be the first to reach these coordinates in Boston. User:zigdon will not be renting a boat to get to the San Francisco point. The San Jose point seems doable though.