Day of the week: Difference between revisions

</pre>

=={{header|MUMPS}}==

{{libheader|VA Kernel|22.0}}

<lang MUMPS>

DOWHOLIDAY

;In what years between 2008 and 2121 will December 25 be a Sunday?

;Uses the VA's public domain routine %DTC (Part of the Kernel) named here DIDTC

NEW BDT,EDT,CHECK,CHKFOR,LIST,I,X,Y

;BDT - the beginning year to check

;EDT - the end year to check

;BDT and EDT are year offsets from the epoch date 1/1/1700

;CHECK - the month and day to look at

;CHKFOR - what day of the week to look for

;LIST - list of years in which the condition is true

;I - the year currently being checked

;X - the date in an "internal" format, for input to DOW^DIDTC

;Y - the output from DOW^DIDTC

SET BDT=308,EDT=421,CHECK="1225",CHKFOR=0,LIST=""

FOR I=BDT:1:EDT SET X=I_CHECK D DOW^DIDTC SET:(Y=0) LIST=$SELECT($LENGTH(LIST):LIST_", ",1:"")_(I+1700)

IF $LENGTH(LIST)=0 WRITE !,"There are no years that have Christmas on a Sunday in the given range."

IF $LENGTH(LIST) WRITE !,"The following years have Christmas on a Sunday: ",LIST

KILL BDT,EDT,CHECK,CHKFOR,LIST,I,X,Y

QUIT

</lang>Usage:<pre>USER>D ^DOW

The following years have Christmas on a Sunday: 2011, 2016, 2022, 2033, 2039, 2044, 2050, 2061, 2067, 2072, 2078, 2089, 2095, 2101, 2107, 2112, 2118