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Posts: 37

# Can someone explain this piece of code in plain language?

I don't think I understand exactly how this piece of code works:

``` if (1 < weekday(date_accident)< 7) then
calc_date_accident = date_accident-1;
else
calc_date_accident = date_accident;```

I understand what it is doing-I know that it is subtracting one day from the date_accident variable, but I don't think I understand what is happening in the "IF" statement, specifically the 1 and 7.

Can someone please explain what this code is actually saying?

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‎01-25-2017 12:57 PM
Posts: 3,852

## Re: Can someone explain this piece of code in plain language?

[ Edited ]

The expression is a shorthand for

`1 < weekday(date_accident) and weekday(date_accident) < 7`

you could also say

`IF weekday(date_accident) NOT IN (1 7);`

Not Saturday or Sunday.  See the WEEKDAY() function documentation.

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Solution
‎01-25-2017 12:57 PM
Posts: 3,852

## Re: Can someone explain this piece of code in plain language?

[ Edited ]

The expression is a shorthand for

`1 < weekday(date_accident) and weekday(date_accident) < 7`

you could also say

`IF weekday(date_accident) NOT IN (1 7);`

Not Saturday or Sunday.  See the WEEKDAY() function documentation.

Contributor
Posts: 37

## Re: Can someone explain this piece of code in plain language?

thanks @data_null__!

So the 1 and the 7 actually represents Saturday and Sunday?

Does that mean I can select any day of the week by using these numbers in conjuction with "weekday". So  for example if I wanted to select Wednesday I would choose the number 4?

Posts: 3,852

## Re: Can someone explain this piece of code in plain language?

[ Edited ]

confused_saser wrote:

thanks @data_null__!

So the 1 and the 7 actually represents Saturday and Sunday?

Does that mean I can select any day of the week by using these numbers in conjuction with "weekday". So  for example if I wanted to select Wednesday I would choose the number 4?

I'm sorry, I assumed you had looked at the documention for the WEEKDAY function and knew what it was returning.  Yes today, Wednesday, is weekday 4.

Contributor
Posts: 37

## Re: Can someone explain this piece of code in plain language?

I should have looked it up but I actualyl dind't realize it was a function.

Super new to SAS! thank you

Posts: 3,852

## Re: Can someone explain this piece of code in plain language?

confused_saser wrote:

I should have looked it up but I actualyl dind't realize it was a function.

Super new to SAS! thank you

I thought your confusion was with the expression 1 < value < 7, it was for me.  I had to write an example to make sure I knew what it was doing.

``````data acc;
do date_accident = today() to today()+10;
weekday = weekday(date_accident);
x = 1 < weekday(date_accident)< 7;
y = 1 < weekday(date_accident) and weekday(date_accident) < 7;
z = weekday(date_accident) not in (1 7);
if (1 < weekday(date_accident)< 7) then calc_date_accident = date_accident-1;
else calc_date_accident = date_accident;
output;
end;
run;
proc print;
run;``````

Valued Guide
Posts: 2,191

## Re: Can someone explain this piece of code in plain language?

Thought you might (at cost of a little complexity) have reduced the code to

Calc_date_accident = date_accident - not ( weekday( date_accident ) in( 1, 7 ) ) ;

Since the results of SAS logical operations are either 0 or 1, the composite above achieves what appears to be wanted....

I'm just interested in what activity requires this adjustment for Monday to Friday but not for Saturday and Sunday....?
☑ This topic is solved.