Solved

# How to get weeknumbers from a date-serial number

Posted on 2001-07-12
Medium Priority
224 Views
Hi,

I have a variable with a date serial in it.
For example: Friday, July 13 8:00 AM is in serial 995004000.
What I would like is to get the weeknumber out of this serial number. And Friday, July 13th is weeknumber 28.
Is there someone who can help me solving this problem?

Thanks,
Hinke
0
Question by:hinkeltje
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LVL 4

Expert Comment

ID: 6279657
how do you get 995004000 from Friday, July 13 8:00 AM? is that a unix timestamp?
0

Author Comment

ID: 6279667
Yes it is.
0

Author Comment

ID: 6279678
Yes it is.
0

LVL 4

Expert Comment

ID: 6279690
try this:

<?
\$your_time = 995004000;
\$day = date("j",\$your_time);
\$month = date("n",\$your_time);
\$year = date("Y",\$your_time);
\$total_days = \$day;

for(\$i=1;\$i<=\$month;\$i++)
{
\$total_days = \$total_days + date("t",mktime (0,0,0,\$day,\$month,\$year));
}

\$number_of_weeks = \$total_days / 7;
?>
0

Author Comment

ID: 6279712
It's not giving me the correct answer.
\$number_of_weeks has result 32.857142857143
But 995004000 is in week 28.
0

LVL 4

Expert Comment

ID: 6279749
OK sorry some technical mistake. This should work very fine.

<?
\$your_time = 995004000;
\$day = date("j",\$your_time);
\$month = date("n",\$your_time);
\$total_days = \$day;

for(\$i=1;\$i<\$month;\$i++)
{
\$total_days = \$total_days + date("t",mktime (0,0,0,\$i,\$day,\$year));
}
\$number_of_weeks = round(\$total_days / 7);
echo \$number_of_weeks;
?>
0

Author Comment

ID: 6279783
Ok, this is giving me the correct result back for Friday 13 July.
But if I give Mon 9th July, it gives me week 27, but Mon 9th July is still week 28.
It seems that your week ends on wednesday and starts on thursday. But (ofcourse) it need to start on mondays and ending on sundays.
0

LVL 4

Expert Comment

ID: 6279804
ok try this again: :)

<?
\$your_time = mktime (0,0,0,7,1,2001);
\$day = date("j",\$your_time);
\$month = date("n",\$your_time);
\$total_days = \$day;

for(\$i=1;\$i<\$month;\$i++)
{
\$total_days = \$total_days + date("t",mktime (0,0,0,\$i,\$day,\$year));
}
\$remainder = (\$total_days / 7) - round(\$total_days / 7);
\$number_of_weeks = round(\$total_days / 7);
if(\$remainder > 0 && \$remainder < 0.5)
\$number_of_weeks = \$number_of_weeks + 1;
echo \$number_of_weeks;
?>
0

Author Comment

ID: 6279826
I think we are almost there :-)
But your week starts at sunday, and I want my week to start on monday.

So for example:
week 27  mon July 2nd till sun July 8th
week 28  mon July 9th till sun July 15th
week 29  mon July 16th till sun July 22nd
0

LVL 4

Expert Comment

ID: 6279901
ok gotcha:

<?
\$your_time = mktime (0,0,0,7,22,2001);
\$day = date("j",\$your_time);
\$month = date("n",\$your_time);
\$total_days = \$day;

for(\$i=1;\$i<\$month;\$i++)
{
\$total_days = \$total_days + date("t",mktime (0,0,0,\$i,\$day,\$year));
}
\$remainder = (\$total_days / 7) - round(\$total_days / 7);
\$number_of_weeks = round(\$total_days / 7);

if(\$remainder > 0.15 && \$remainder < 0.65)
\$number_of_weeks = \$number_of_weeks + 1;
echo \$number_of_weeks;
?>
0

Author Comment

ID: 6279977
Thanks, this seems to work. But.... you use:
mktime (0,0,0,7,15,2001)
And I am using: 995004000
And if I use the integer above, it gives me back week 28 all the time.
0

LVL 4

Expert Comment

ID: 6279982
That number is a constant and sure enough it gives 28 all the time because that number represents 13th July 2001 which is the 28th week.
0

LVL 4

Accepted Solution

ykf2000 earned 800 total points
ID: 6279989
if you wanna have different timestamps, let's you want todays time stamp then use

\$today_timestamp = mktime(0,0,0,date("n"),date("j"),date("Y"));
0

Author Comment

ID: 6279990
Yeah duh... and if I change the number (let's say add an extra 10 days) it still gives me back week 28.
0

LVL 4

Expert Comment

ID: 6279998
what do u mean add another 10 days? You can't just add 10 to that number. It does not work that way.
0

Author Comment

ID: 6280010
I can add an extra 10 days to that number :-)

time()+(86400*10)
It is representing today plus an extra 10 days.

And 86400 comes from 86400 seconds in one day: 24 * 60 * 60
0

Author Comment

ID: 6280023
Thank you ykf2000 for your help (and time).
It works perfect now.
0

LVL 4

Expert Comment

ID: 6280026
great :)
0

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