samples/mothers_day.js

# compute Mothers day of the given the year

/*
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// print "Mother's day" of the given year using Java Time API

if (arguments.length == 0) {
    print("Usage: jjs mothers_day.js -- year");
    exit(1);
}

// java classes used
var DayOfWeek = java.time.DayOfWeek;
var LocalDate = java.time.LocalDate;
var TemporalAdjusters = java.time.temporal.TemporalAdjusters;

var year = parseInt(arguments[0]);

// See: https://en.wikipedia.org/?title=Mother%27s_Day
// We need second Sunday of May. Make April 30 of the given
// year adjust and adjust to next Sunday from there twice. To adjust a Date
// we use a common TemporalAdjuster provided in JDK8.
// https://docs.oracle.com/javase/8/docs/api/java/time/temporal/TemporalAdjusters.html

print(LocalDate.of(year, 4, 30).
    with(TemporalAdjusters.next(DayOfWeek.SUNDAY)).
    with(TemporalAdjusters.next(DayOfWeek.SUNDAY)));