Description of Twitter data set.

Time stamps in Euro14 and Italy are in local time while time stamps in Bulgaria13 are in Greenwich Mean Time (GMT). There is a three-hours difference between GMT and Bulgarian time. Ti represents the initial day of considered data. Te is the election day. Tf represents the final day of considered data. One-day is defined a time interval from 00:00:00 to 23:59:59 in considered time. NT represents the total number of considered tweets for given time interval from Ti to Te-1 posted in local language. NP represents the number of considered political parties.