Identifying the season from the Date using Java

Question

I've had nothing but good luck from SO, so why not try again?

I have an application that needs to show a different image based on the season of the year (spring, summer, winter, fall). I have very specific start and end dates for these seasons.

What I would like from you geniuses is a method called GetSeason that takes a date as input and returns a String value of Spring, Summer, Winter or Fall. Here are the date ranges and their associated seasons:

Spring:3/1-4/30
Summer:5/1-8/31
Fall:9/1-10/31
Winter: 11/1-2/28

Can someone provide a working method to return the proper season? Thanks everyone!

Answer 1

Well, it could be as simple as

String getSeason(int month) {
    switch(month) {
          case 11:
          case 12:
          case 1:
          case 2:
                return "winter";
          case 3:
          case 4:
                return "spring";
          case 5:
          case 6:
          case 7:
          case 8:
                return "summer";
          default:
                return "autumn";
      }
}

I have been chided in the comments into a better solution: enums:

public static Enum Season {
    WINTER(Arrays.asList(11,12,1,2)),
    SPRING(Arrays.asList(3,4)),
    SUMMER(Arrays.asList(5,6,7,8)),
    AUTUMN(Arrays.asList(9,10));

    Season(List<Integer> months) {
        this.monthlist = months;
    }
    private List<Integer> monthlist;
    public boolean inSeason(int month) {
        return this.monthlist.contains(month);  // if months are 0 based, then insert +1 before the )
    }

    public static Season seasonForMonth(int month) {
        for(Season s: Season.values()) {
            if (s.inSeason(month))
                 return s;
        }
        throw new IllegalArgumentException("Unknown month");
    }
}

Answer 2

since in this range all seasons are full months, you can do a switch with the month from your date:

switch (date.getMonth()) {
    case Calendar.JANUARY:
    case Calendar.FEBRUARY:
         return "winter";
    case Calendar.MARCH:
         return "spring";
    //etc
}

I recommend completing the entire switch using all 12 Calendar constants, instead of default for the last ones. You can then make sure your input was correct, for example with

default:
 throw new IllegalArgumentException();

at the end.

You might also want to use an Enum for the season, instead of a simple string, depending on your use cases.

Note the Date.getMonth() method is deprecated, you should use java.util.Calendar.get(Calendar.MONTH) instead. (just convert the Date to a Calendar using calendar.setDate(yourDate))

Answer 3

Seems like just checking the month would do:

private static final String seasons[] = {
  "Winter", "Winter", "Spring", "Spring", "Summer", "Summer", 
  "Summer", "Summer", "Fall", "Fall", "Winter", "Winter"
};
public String getSeason( Date date ) {
   return seasons[ date.getMonth() ];
}

// As stated above, getMonth() is deprecated, but if you start with a Date, 
// you'd have to convert to Calendar before continuing with new Java, 
// and that's not fast.

Answer 4

i feel patronized, but flattered. so i'll do it.

This checks not only the month, but day of month.

import java.util.*

public String getSeason(Date today, int year){

    // the months are one less because GC is 0-based for the months, but not days.
    // i.e. 0 = January.
    String returnMe = "";

    GregorianCalender dateToday = new GregorianCalender(year, today.get(Calender.MONTH_OF_YEAR), today.get(Calender.DAY_OF_MONTH);
    GregorianCalender springstart = new GregorianCalender(year, 2, 1);
    GregorianCalender springend = new GregorianCalender(year, 3, 30);
    GregorianCalender summerstart = new GregorianCalender(year, 4, 1);
    GregorianCalender summerend = new GregorianCalender(year, 7, 31);
    GregorianCalender fallstart = new GregorianCalender(year, 8, 1);
    GregorianCalender fallend = new GregorianCalender(year, 9, 31);
    GregorianCalender winterstart = new GregorianCalender(year, 10, 1);
    GregorianCalender winterend = new GregorianCalender(year, 1, 28);

    if ((dateToday.after(springstart) && dateToday.before(springend)) || dateToday.equals(springstart) || dateToday.equals(springend)){
        returnMe = "Spring";

    else if ((dateToday.after(summerstart) && dateToday.before(summerend)) || dateToday.equals(summerstart) || dateToday.equals(summerend)){
        returnMe = "Summer";

    else if ((dateToday.after(fallstart) && dateToday.before(fallend)) || dateToday.equals(fallstart) || dateToday.equals(fallend)){
        returnMe = "Fall";

    else if ((dateToday.after(winterstart) && dateToday.before(winterend)) || dateToday.equals(winterstart) || dateToday.equals(winterend)){
        returnMe = "Winter";

    else {
        returnMe = "Invalid";
    }
    return returnMe;
}

I'm sure this is hideous, and can be improved. let me know in the comments.