Last Friday of each month: Difference between revisions

</pre>

=={{header|K}}==

<lang K>

/ List the dates of last Fridays of each month of

/ a given year

/ lastfridt.k

isleap: {(+/~x!' 4 100 400)!2}

wd: {(_jd x)!7}

dom: (31;28;31;30;31;30;31;31;30;31;30;31)

init: {:[isleap x;dom[1]::29;dom[1]::28]}

wdme: {[m;y]; init y; dt:(10000*y)+(100*m)+dom[m-1];jd::(_jd dt);mewd::(wd dt)}

lfd: {[m;y]; wdme[m;y];:[mewd>3;jd::jd+(4-mewd);jd::jd-(3+mewd)];dt:_dj(jd);yy:$(yr:dt%10000);dd:$(d:dt!100);mm:$(mo:((dt-yr*10000)%100));arr::arr,`$(yy,"-",mm,"-",dd)}

lfd1: {[y];arr::(); m:1; do[12;lfd[m;y];m+:1]}

main: {[y]; lfd1[y]; arr}

</lang>

The output of a session is given below:

{{out}}

<pre>

K Console - Enter \ for help

\l lastfridt

main 2000

`"2000-1-28" `"2000-2-25" `"2000-3-31" `"2000-4-28" `"2000-5-26" `"2000-6-30" `"

2000-7-28" `"2000-8-25" `"2000-9-29" `"2000-10-27" `"2000-11-24" `"2000-12-29"

main 2007

`"2007-1-26" `"2007-2-23" `"2007-3-30" `"2007-4-27" `"2007-5-25" `"2007-6-29" `"

2007-7-27" `"2007-8-31" `"2007-9-28" `"2007-10-26" `"2007-11-30" `"2007-12-28"

main 2018

`"2018-1-26" `"2018-2-23" `"2018-3-30" `"2018-4-27" `"2018-5-25" `"2018-6-29" `"

2018-7-27" `"2018-8-31" `"2018-9-28" `"2018-10-26" `"2018-11-30" `"2018-12-28"

main 2012

`"2012-1-27" `"2012-2-24" `"2012-3-30" `"2012-4-27" `"2012-5-25" `"2012-6-29" `"

2012-7-27" `"2012-8-31" `"2012-9-28" `"2012-10-26" `"2012-11-30" `"2012-12-28"