The International Telegraph Union (ITU), later renamed as the International Telecommunication Union, was founded on 1865-05-17. The ITU became a United Nations specialised agency in 1947. Following the 100th anniversary of the founding of the ITU on 1965-05-17, an annual World Telecommunication Day (WTD) was established, to be held on 17 May each year. The first WTD was held on 1969-05-17. In 2005, WTD was renamed World Information Society Day. An amateur radio station is operated from the ITU HQ in Geneva to mark WTD, using a callsign in the series 4U#ITU. The table below lists these callsigns.

Year Callsign Note 
1965  4U1ITU, 4U2ITU, 4U3ITU, 4U4ITU, 4U5ITU, 4U6ITU  100th anniversary of the founding of the ITU 
1969 4U7ITU  First World Telecommunication Day
1970  4U7ITU   
1971  4U3ITU  
1972 4U4ITU   
1973 - Apparently not QRV
1974  4U6ITU 

1975 4U7ITU

110th anniversary of ITU

1976 4U8ITU  


1978 4U0ITU, 4U1ITU 10th World Telecommunication Day
1979 4U1ITU  
1980 4U5ITU  
1981 4U6ITU  
1982 4U7ITU  
1983 4U8ITU  


1985 4U0ITU 120th anniversary of ITU
1986  4U1ITU  
1987 4U2ITU  
1988 4U3ITU  20th World Telecommunication Day 
1989 4U4ITU   
1990  4U5ITU  
1991 4U6ITU   
1992 4U7ITU   
1993 4U8ITU  
1994  4U9ITU   
1995 4U0ITU 

130th anniversary of ITU

1996  4U1ITU  
1997 4U1ITU   
1998 4U1ITU 

30th World Telecommunication Day





2001 4U1ITU    
2002  4U1ITU    
2003  4U1ITU    
2004  4U1ITU    


Wikipedia - International Telecommunication Union

Wikipedia - World Information Society Day