2000 was designated as the International Year for the Culture of Peace and the World Mathematical Year. Popular culture holds the year 2000 as the first year of the 21st century and the 3rd millennium, because of a tendency to group the years according to decimal values, as if year zero were counted. According to the Gregorian calendar, these distinctions fall to the year 2001, because the 1st century was retroactively said to start with the year AD 1. Since the Gregorian calendar does not have year zero, its first millennium spanned from years 1 to 1000 inclusively and its second millennium from years 1001 to 2000. (For further information, see century and millennium.) The year 2000 is sometimes abbreviated as "Y2K" (the "Y" stands for "year", and the "K" stands for "kilo" which means "thousand"). The year 2000 was the subject of Y2K concerns, which were fears that computers would not shift from 1999 to 2000 correctly. However, by the end of 1999, many companies had already converted to new, or upgraded, existing software. Some even obtained "Y2K certification". As a result of massive effort, relatively few problems occurred. Events January January 6 – The last naturally-conceived Pyrenean ibex is found dead, apparently killed by a falling tree. January 10 – America Online announces an agreement to purchase Time Warner for $162 billion (the largest-ever corporate merger). January 14 The Dow Jones Industrial Average closes at 11,722.98 (at the peak of the Dot-com bubble). The United Nations' International Criminal Tribunal for the former Yugoslavia sentences five Bosnian Croats to up to 25 years in prison for the 1993 killing of more than 100 Bosnian Muslims. January 30 – Kenya Airways Flight 431 crashes off the Ivory Coast into the Atlantic Ocean, killing 169 people. January 31 – Alaska Airlines Flight 261 crashes off the California coast into the Pacific Ocean; all 88 passengers and crew are killed. February February 5 – Second Chechen War: Novye Aldi massacre – Russian forces summarily execute 56-60 civilians in a suburb of Grozny. February 6 – Second Chechen War: Battle of Grozny (1999–2000) ends as Russian forces conclude capture of the Chechen capital Grozny. February 9 – Torrential rains in Africa lead to the worst flooding in Mozambique in 50 years, which lasts until March and kills 800 people. February 21 – UNESCO holds the inaugural celebration of International Mother Language Day. February