Get day name from full calender date format

Question

How to get name day name like (Wednesday - Thursday) from this date format "Wed Jan 30 00:00:00 GMT+02:00 2019"

Answer 1

java.time

It seems that what you’ve got is an instance of the java.util.Date class. That’s a poorly designed class that is long outdated, so first thing is to see if you can avoid that and have an instance of a class from java.time, the modern Java date and time API, instead.

However, if you got the Date from a legacy API that you cannot change or don’t want to change just now, first thing is to convert it to a modern Instant and then perform further conversions from there. The following snippet uses ThreeTenABP, more on that below.

    Date yourOldfashionedDate = getFromLegacyApi();

    Instant modernInstant = DateTimeUtils.toInstant(yourOldfashionedDate);
    String dayName = modernInstant.atZone(ZoneId.systemDefault())
            .getDayOfWeek()
            .getDisplayName(TextStyle.FULL, Locale.ENGLISH);

    System.out.println("Day name is " + dayName);

Output given the date from your question:

Day name is Wednesday

If what you got was a String (probably a string returned from Date.toString at some point), you need to parse it first:

    DateTimeFormatter dateFormatter
            = DateTimeFormatter.ofPattern("EEE MMM dd HH:mm:ss zzz yyyy", Locale.ROOT);

    String dateString = "Wed Jan 30 00:00:00 GMT+02:00 2019";
    ZonedDateTime dateTime = ZonedDateTime.parse(dateString, dateFormatter);
    String dayName = dateTime.getDayOfWeek()
            .getDisplayName(TextStyle.FULL, Locale.ENGLISH);

You see that the last bit is exactly like before.

Question: Can I use java.time on Android?

Yes, java.time works nicely on older and newer Android devices. It just requires at least Java 6.

• In Java 8 and later and on newer Android devices (from API level 26) the modern API comes built-in. Only in this case use yourOldfashionedDate.toInstant() instead of DateTimeUtils.toInstant(yourOldfashionedDate).
• In Java 6 and 7 get the ThreeTen Backport, the backport of the modern classes (ThreeTen for JSR 310; see the links at the bottom).
• On (older) Android use the Android edition of ThreeTen Backport. It’s called ThreeTenABP. And make sure you import the date and time classes from org.threeten.bp with subpackages.

Links

• Oracle tutorial: Date Time explaining how to use java.time.
• Java Specification Request (JSR) 310, where java.time was first described.
• ThreeTen Backport project, the backport of java.time to Java 6 and 7 (ThreeTen for JSR-310).
• ThreeTenABP, Android edition of ThreeTen Backport
• Question: How to use ThreeTenABP in Android Project, with a very thorough explanation.

Answer 2

You can use SimpleDateFormat for it and the format part that gives you the full day name is EEEE. Hope it helps!

Answer 3

You will need to first parse your String into a Calendar object using a SimpleDateFormat :

Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("EEE MMM dd HH:mm:ss z yyyy", Locale.ENGLISH);
try {
    cal.setTime(sdf.parse("Wed Jan 30 00:00:00 GMT+02:00 2019"));
} catch (ParseException e) {
    // Log invalid date format
}

Then extract the day from your Calendar object:

String day = cal.getDisplayName(Calendar.DAY_OF_WEEK,Calendar.LONG,Locale.ENGLISH);

Answer 4

## Here, I have attached a method that will give you expected output ##

public void dayName(){
    String weekDay,time;
    SimpleDateFormat dayFormat = new SimpleDateFormat("EEEE MMM dd HH:mm", Locale.US);
    SimpleDateFormat dayFormat1 = new SimpleDateFormat("hh:mm yyyy", Locale.US);
    dayFormat.setTimeZone(TimeZone.getTimeZone("ITC"));
    dayFormat1.setTimeZone(TimeZone.getTimeZone("GMT"));
        Calendar calendar = Calendar.getInstance();
        weekDay = dayFormat.format(calendar.getTime());
        time=dayFormat1.format(calendar.getTime());
        Log.e(TAG, "dayName: "+weekDay+" GMT+"+time );// out put looks like : Tuesday Jan 29 17:58 GMT+05:58 2019

}

• I have used two TimeZone are ITC and GMT