Android - Formatting Date and Time.

Date and Time formatting Cheat Sheet

Symbol	Meaning	Type	Type
G	Era	Text	GG->AD
Y	Year	Number	yy -> 03, yyyy -> 2003
M	Month	Text or Number	M -> 7, MM -> 07, MMM -> Jul , MMMM -> July
d	Day in month	Number	d -> 3 , dd -> 03
h	Hour (1-12, AM/PM)	Number	h -> 3 , hh -> 03
H	Hour (0-23)	Number	H -> 15 , HH -> 15
k	Hour (1-24)	Number	k -> 3 , kk -> 03
K	Hour (0-11 AM/PM)	Number	K -> 15 , KK -> 15
m	Minute	Number	m -> 7 , m -> 15 , mm -> 15
s	Second	Number	s -> 15 , ss -> 15
S	Millisecond (0-999)	Number	SSS -> 007
E	Day in week	Text	EEE -> Tue , EEEE -> Tuesday
D	Day in yr(1-365,1-364)	Number	D -> 65 , DDD -> 065
F	Day of week in month (1-5)|	Number	F -> 1
w	Week in year (1-53)	Number	w -> 7
a	AM/PM	Text	a -> AM , aa -> AM
z	Time zone	Text	z -> EST , zzz -> EST , zzzz -> Eastern Standard Time

Some sample of date format

 String DATE_FORMAT_1 = "dd-MMM-yyyy kk:mm";
 String DATE_FORMAT_2 = "yyyy-MM-dd HH:mm:ss";
 String DATE_FORMAT_3 = "yyyy-MM-dd";
 String DATE_FORMAT_4 = "dd-MMM-yyyy"; 
 String DATE_FORMAT_5 = "dd_MM_yyyy"; 
 String DATE_FORMAT_6 = "yyyy-MM-dd'T'HH:mm:ss"; 
 String DATE_FORMAT_7 = "yyyy-MM-dd'T'HH:mm:ss.SSSSSS'Z'"; 

1. Get today date.

Example - 1
 public String getCurrentTimeStr() { 
    return new SimpleDateFormat(DATE_FORMAT_1, Locale.US).format(new Date())
 }

2. Compare dates.

Example - 2
public boolean isFutureDate(String originalDate) {
        boolean isFuture = false; 
         SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT_1, Locale.US);           Date dateObj; 
         try { 
               dateObj = sdf.parse(originalDate);
                if (new Date().before(dateObj)) { 
                     isFuture = true;
                } 
          } catch (ParseException e) { 

         }
     return isFuture
 }

3. Convert UTC to Local date UTC is the common time standard across the world.

Example - 3
 public String convertUtcToLocal(String dateTime) { 
       String do = "";
       if(dateTime !=null){ 
           DateFormat originalFormat = new SimpleDateFormat(DATE_FORMAT_2, Locale.US);
            originalFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
            DateFormat targetFormat = new SimpleDateFormat(DATE_FORMAT_2, Locale.US); 
        targetFormat.setTimeZone(TimeZone.getDefault())
         try { 
            Date date = originalFormat.parse(dateTime); 
            dob = targetFormat.format(date);
          } catch (ParseException e) { 
       }
     }
    return do;
 }

4. Merge Date and time

private static final String DATE_TIME = "d MMM yyyy HH:mm";

Example - 4
 public  Date getTrainStartTime(String originalDate, String time) {
        String mAlertDateTime = originalDate + " " + time;
        SimpleDateFormat dft = new SimpleDateFormat(DATE_TIME, Locale.getDefault());
        try {
            Date d = dft.parse(mAlertDateTime);
            return d;
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return new Date();
 }