function t=utc(zone,isdls,format)
%UTC  Get current UTC time.
%   T = UTC(ZONE,ISDLS,FORMAT)  returns the current UTC
%   (or GMT) time in the format FORMAT given the locations
%   time zone ZONE, daylight saving on/off ISDLS and output
%   format FORMAT, which can be either of
%
%      'D'      : serial date number
%      'YMDhms' : date vector
%      'hms'    : hour, minute, second -vector
%      's'      : seconds since AD (default).
%
%   See also DAYLIGHT, DATEVEC, DATENUM, CLOCK.

% Copyright (c) 2002-12-08, B. Rasmus Anthin.
% Revisited 2003-06-18.

time=clock;
cmp=zone+daylight(zone,isdls);
time(3)=time(3)-(time(4)-cmp < 0);
time(4)=mod(time(4)-cmp,24);
td=datenum(time(1),time(2),time(3),time(4),time(5),time(6));
switch format
case 'D'
   t=td;
case 'YMDhms'
   t=time;
case 'hms'
   t=time(4:6);
otherwise   % case 's'
   t=td*24*3600;
end