Determining a season from a date using Java

Question

I had nothing but luck with SO, so why not try again?

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

What I would like from you, genius, is a method called GetSeason that takes a date as input and returns a String Spring, summer, winter, or fall. Below are the date ranges and their 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 for returning the relevant season? Thanks everyone!

Answer 1

It seems like just checking the month:

private static final String seasons[] = { "Winter", "Winter", "Spring", "Spring", "Spring", "Summer", "Summer", "Summer", "Fall", "Fall", "Fall", "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 not fast. 

Answer 2

Some good answers are here, but they are out of date. The java.time classes make this work a lot easier.

java.time

The inconvenient old classes associated with the earliest versions of Java have been superseded by the java.time classes built into Java 8 and later. See Oracle Tutorial . Most of the functionality was ported to Java 6 and 7 in ThreeTen-Backport and further adapted for Android in ThreeTenABP .

Month

Given that seasons are determined here for whole months, we can use the convenient Month enum . Such enumeration values ​​are better than simple integer values ​​(1-12), because they are type safe and you are guaranteed valid values.

EnumSet

An EnumSet is a fast and compact way to track a subset of enum values.

 EnumSet<Month> spring = EnumSet.of( Month.MARCH , Month.APRIL ); EnumSet<Month> summer = EnumSet.of( Month.MAY , Month.JUNE , Month.JULY , Month.AUGUST ); EnumSet<Month> fall = EnumSet.of( Month.SEPTEMBER , Month.OCTOBER ); EnumSet<Month> winter = EnumSet.of( Month.NOVEMBER , Month.DECEMBER , Month.JANUARY , Month.FEBRUARY ); 

As an example, we get the current moment for a specific time zone.

 ZoneId zoneId = ZoneId.of( "America/Montreal" ); ZonedDateTime zdt = ZonedDateTime.now( zoneId ); 

Set this date value for your Month .

 Month month = Month.from( zdt ); 

See which season the EnumSet has this particular month value by calling contains .

 if ( spring.contains( month ) ) { … } else if ( summer.contains( month ) ) { … } else if ( fall.contains( month ) ) { … } else if ( winter.contains( month ) ) { … } else { // FIXME: Handle reaching impossible point as error condition. } 

Define Your Own Season List

If you use the idea of ​​this season around your code base, I suggest defining your own enum, "Season".

The main listing is simple: public enum Season { SPRING, SUMMER, FALL, WINTER; } public enum Season { SPRING, SUMMER, FALL, WINTER; } . But we also add a static of method to find which cards of the month are in which season.

 package com.example.javatimestuff; import java.time.Month; public enum Season { SPRING, SUMMER, FALL, WINTER; static public Season of ( Month month ) { switch ( month ) { // Spring. case MARCH: // Java quirk: An enum switch case label must be the unqualified name of an enum. So cannot use `Month.MARCH` here, only `MARCH`. return Season.SPRING; case APRIL: return Season.SPRING; // Summer. case MAY: return Season.SUMMER; case JUNE: return Season.SUMMER; case JULY: return Season.SUMMER; case AUGUST: return Season.SUMMER; // Fall. case SEPTEMBER: return Season.FALL; case OCTOBER: return Season.FALL; // Winter. case NOVEMBER: return Season.WINTER; case DECEMBER: return Season.WINTER; case JANUARY: return Season.WINTER; case FEBRUARY: return Season.WINTER; default: System.out.println ( "ERROR." ); // FIXME: Handle reaching impossible point as error condition. return null; } } } 

Here's how to use this listing.

 ZoneId zoneId = ZoneId.of ( "America/Montreal" ); ZonedDateTime zdt = ZonedDateTime.now ( zoneId ); Month month = Month.from ( zdt ); Season season = Season.of ( month ); 

Dump for the console.

 System.out.println ( "zdt: " + zdt + " | month: " + month + " | season: " + season ); 

zdt: 2016-06-25T18: 23: 14.695-04: 00 [America / Montreal] | month: JUNE | season: SUMMER

Answer 3

Well, it can 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 was rebuked in the comments for 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 4

I feel like a patron, but flattered. so i will do it.

This checks not only the month, but also the day of the 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. // ie 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 am sure this is disgusting and can be improved. let me know in the comments.

Answer 5

 import java.util.Scanner; public class lab6project1 { public static void main(String[] args) { Scanner keyboard = new Scanner(System.in); System.out.println("This program reports the season for a given day and month"); System.out.println("Please enter the month and day as integers with a space between the month and day"); int month = keyboard.nextInt(); int day = keyboard.nextInt(); if ( (month == 1) || (month == 2)) System.out.println("The season is Winter"); else if ( (month == 4) || (month == 5)) System.out.println("The season is Spring"); else if ( (month == 7) || (month == 8)) System.out.println("The season is Summer"); else if ( (month == 10)|| (month == 11)) System.out.println("The season is Fall"); else if ( (month == 3) && (day <= 19 )) System.out.println("The season is Winter"); else if ( (month == 3) && (day >= 20 )) System.out.println("The season is Spring"); else if ( (month == 6) && (day <= 20 )) System.out.println("The season is Spring"); else if ( (month == 6) && (day >= 21 )) System.out.println("The season is Summer"); else if ( (month == 9) && (day <= 20 )) System.out.println("The season is Summer"); else if ( (month == 9) && (day >= 21 )) System.out.println("The season is Autumn"); else if ( (month == 12) && (day <= 21 )) System.out.println("The season is Autumn"); else if ( (month == 12) && (day >= 22 )) System.out.println("The season is Winter"); } } 

Answer 6

Try using hash tables or enumerations. You can convert the date to some value (jan 1 - 1, ...) and then create cells for a specific field. or you can do the listing with the month. {January: winter, February: winter, ... July: summer, etc.}

Answer 7

since in this range all seasons are full months, you can make the transition 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 populating the entire switch using all 12 calendar constants, not the default for the latter. Then you can make sure that your input is correct, for example with

 default: throw new IllegalArgumentException(); 

in the end.

You can also use Enum for the season instead of a simple string depending on your use cases.

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

Answer 8

A simple solution

  Calendar calendar = Calendar.getInstance(); calendar.setTimeInMillis(timeInMills); int month = calendar.get(Calendar.MONTH); CurrentSeason = month == 11 ? 0 : (month + 1) / 3; 

Answer 9

The name of your question is very general, so most users will first think about the astronomical seasons. Although the detailed content of your question is limited by custom date ranges, this restriction may be caused by the inability to calculate the astronomical case, so I dare to send an answer to this old question also for the astronomical scenario.

And most of the answers here are based on full months only. I will give two examples here to consider both astronomical seasons and seasons based on arbitrary date ranges.

a) mapping of arbitrary date ranges by season

Here we definitely need additional information, a specific time zone or offset, otherwise we cannot instantly translate (for example, oldfashioned java.util.Date -instance of your input) into a local view using a combination of month and day. For simplicity, I accept the system time zone.

  // your input java.util.Date d = new java.util.Date(); ZoneId tz = ZoneId.systemDefault(); // extract the relevant month-day ZonedDateTime zdt = d.toInstant().atZone(tz); MonthDay md = MonthDay.of(zdt.getMonth(), zdt.getDayOfMonth()); // a definition with day-of-month other than first is possible here MonthDay beginOfSpring = MonthDay.of(3, 1); MonthDay beginOfSummer = MonthDay.of(5, 1); MonthDay beginOfAutumn = MonthDay.of(9, 1); MonthDay beginOfWinter = MonthDay.of(11, 1); // determine the season Season result; if (md.isBefore(beginOfSpring)) { result = Season.WINTER; } else if (md.isBefore(beginOfSummer)) { result = Season.SPRING; } else if (md.isBefore(beginOfAutumn)) { result = Season.SUMMER; } else if (md.isBefore(beginOfWinter)) { result = Season.FALL; } else { result = Season.WINTER; } System.out.println(result); 

I used a simple helper enum like public enum Season { SPRING, SUMMER, FALL, WINTER; } public enum Season { SPRING, SUMMER, FALL, WINTER; } public enum Season { SPRING, SUMMER, FALL, WINTER; } public enum Season { SPRING, SUMMER, FALL, WINTER; } .

b) astronomical seasons

Here we also need additional information, namely: i) the gregorian year associated with this, because the astronomical season may change slightly over time and ii) if the season is in the north or in the southern hemisphere. My Time4J library offers the following solution based on AstronomicalSeason's predefined enumeration:

  // your input java.util.Date d = new java.util.Date(); boolean isSouthern = false; Moment m = Moment.from(d.toInstant()); int year = m.toLocalTimestamp().getYear(); // uses the system timezone // first calculate relevant moments for the northern hemisphere Moment beginOfSpring = AstronomicalSeason.VERNAL_EQUINOX.inYear(year); Moment beginOfSummer = AstronomicalSeason.SUMMER_SOLSTICE.inYear(year); Moment beginOfAutumn = AstronomicalSeason.AUTUMNAL_EQUINOX.inYear(year); Moment beginOfWinter = AstronomicalSeason.WINTER_SOLSTICE.inYear(year); // determine the season AstronomicalSeason result; if (m.isBefore(beginOfSpring)) { result = AstronomicalSeason.WINTER_SOLSTICE; } else if (m.isBefore(beginOfSummer)) { result = AstronomicalSeason.VERNAL_EQUINOX; } else if (m.isBefore(beginOfAutumn)) { result = AstronomicalSeason.SUMMER_SOLSTICE; } else if (m.isBefore(beginOfWinter)) { result = AstronomicalSeason.AUTUMNAL_EQUINOX; } else { result = AstronomicalSeason.WINTER_SOLSTICE; } if (isSouthern) { // switch to southern equivalent if necessary result = result.onSouthernHemisphere(); } System.out.println(result); 

Note The next version of v5.2 Time4J will contain an optimized and simplified factory method for getting the season from the moment. And the system time zone used to calculate the corresponding year is in order (instead of any other time zone), because the astronomical season does not change around the New Year.