Day count for this date (2003-10-08) is 280.

e.g. 
# php -r 'echo date("z");'
280

It's propably mcal that is broken. (and I mean the library, not extension)

And RTFM: yday == 0-366 days

Month / days (2003) 
 
Jan: 31 
Feb: 28 
Mar: 31 
Apr: 30 
May: 31 
Jun: 30 
Jul: 31 
Aug: 31 
Sep: 30 
TOTAL: 273 days 
 
Currently 8th of Oct, 2003, thus 
PLUS 8 days (273 + 8). So today is day: 281 
 
Thus, in my humble opinion, mcal_day_of_year() seem 
correct, getdate() seems not to be. But, if getdate() is 
correct, then that makes all the calendars and organizers, 
paper and computer, incorrect when they state Oct 8, 2003, 
as being day '281' and not '280'. 
 
I did "RTFM" as you had suggested. "0-366" just indicates 
the number range, correct? 
 
Cheers, 
Andrew Skripshak

And, IMHO, the example you gave, 
echo date("z"); 
thus also seems to give incorrect results.

Maybe this clears it for you:
# php -r 'echo date("z", mktime(1,1,1,1,1,2003));'
0

The count starts from 0..

Yes, I figured the count started from zero, but really it 
shouldn't. The 1st of the 1st of any year should be day # 
1, not day # 0. 
 
The manuals state that 'yday' in getdate() and 'z' in 
date() give "The day of the year". This is not correct if 
both are out by one day, and no indication that that is the 
case, and no indication that you must add one day to make 
them correct. 
 
The proper fix would be to fix the code, but a slacker fix 
would be to state in the manuals that you must add a day, 
ie., date("z") + 1, to get the correct "day of the year" 
number. 
 
Up to you, of course, which you choose to do. 
 
Cheers, 
Andrew Skripshak

There is no bug and this is how it works in libc provided date() too.

I meant localtime, not date:

# man 3 localtime

And look at the tm_yday section.

Ok, I'll work with it the way it is. 
 
However, there are two things, maybe in other places too, 
which need to be changed. The values in "Example returned 
values" for both date("z") and 'yday' in getdate() show 
"0-366", these should be changed to "0-365" (as is shown in 
the 'man 3 localtime' you gave me to look at). Else there 
be 366 days in a normal year, and 367 in a leap year? 
 
I still believe it should be "1-366", but ah well. 
 
Cheers, 
Andrew Skripshak

It is interesting though, that 'tm_mon' shows "0-11", but 
date() and getdate() use "1-12".

This bug has been fixed in the documentation's XML sources. Since the
online and downloadable versions of the documentation need some time
to get updated, we would like to ask you to be a bit patient.

Thank you for the report, and for helping us make our documentation better.