Determination of the day of the week determined for the latter part of the analysis. By using a given day August 13, 2009 which was a Thursday as a reference, with "Base" and "n" being the number of days and weeks it has been since 01/01/0001 to the given day, respectively and "k" the day into the given week which must be less than 7, "Base" is expressed as Knowing that a year divisible by 4 or 400 is a leap year while a year divisible by 100 and not 400 is not a leap year, a software program can be written to find the number of
IAU 50 km World Championships for those years, moving the competition away from its tradition of changing host each year. The competition signalled commitment to the sport in Qatar, with Doha hosting its first ultramarathon in the months preceding the 2014 championship. It is one of four world championships organised by the IAU, with the others being the IAU 100 km World Championships, IAU 24 Hour World Championship and the IAU Trail Running World Championships. The inaugural edition in 2005 incorporated a European Championship race. Oleg Kharitonov was the men's winner, with World Trophy winner Sandor Barcza as runner-up and Stefano Sartori in third. The