Develop Reference

Date of last connection in Android studio app

I need the date of the last connection. When I enter again I have to see the last date that I entered in my app.
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());
Date date = new Date();
String fecha = dateFormat.format(date);
I have this code but I don't know how to continue.

If I understand your right you can just use System.currentTimeMillis()it looks like this.
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());
Date date = new Date(System.currentTimeMillis());
String fecha = dateFormat.format(date);
Then you can save this value everywhere you want

Simpledateformat is not giving proper date

I want today's date in my application to store it in a database as a string but when i used simpledatefromat and calender.getInstance(), it's not giving me proper date. The code is as below.
I tried simpledateformat's another constructor which takes locale as parameter but still not showing proper date
Date date = Calendar.getInstance().getTime();
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-mm-yyyy");
String dateF = dateFormat.format(date);
expected date should be 21-04-2019
actual result 21-26-2019

To get the month like the way that you want, you need to change "dd-mm-yyyy" to "dd-MM-yyyy"
Date date = Calendar.getInstance().getTime();
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy", Locale.US);
String dateF = dateFormat.format(date);

Getting the current time and date in the device's defined format

How can I get the current time and date according to phone device format?
my code is
Date date = new Date(System.currentTimeMillis());
SimpleDateFormat dateFormat = new SimpleDateFormat("hh:mm aa",
Locale.ENGLISH);
String var = dateFormat.format(date));
It displays like 2PM instead of 14PM.

You can the device format data and time using
Date date = new Date();
DateFormat dateFormat = android.text.format.DateFormat.getDateFormat(getApplicationContext());
Log.d(TAG,dateFormat.format(date)+");

Use calendar object instead of Date because it is deprecated now and by using caledar object you can get hour in 12 hours formate as
int hour = calendarObject.get(Calendar.HOUR);
for 24 formate as:
int hour = calendarObject.get(Calendar.HOUR_OF_DAY);
for further detail you can visit this

Just change "hh:mm aa" to "HH:mm aa"

Comparison of Date and Time

I have to get count of days which are past to the current day.I have list of days in arraylist.I got the list and I dont know how to compare?Can anyone help me?
This is the code I tried,
private void weeklylogeval(){
int i;
DateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
dateFormatter.setLenient(false);
Date today = new Date();
String s = dateFormatter.format(today);
System.out.println("current date & time new:::"+s);
for(i=0;i<datetime.size();i++){
String daytime=datetime.get(i);
if(today.before(daytime))
}
}
Pls some one help me!

Try this code for date difference manipulation.
String fd=from_date;//date get from mysql database as string.
String td=to_date;//Today's date as string.
if(!fd.equalsIgnoreCase("") && !td.equalsIgnoreCase("")){
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
SimpleDateFormat formatter;
Date frmdt=new Date(fd);
formatter = new SimpleDateFormat("dd/MM/yyyy");
String s1 = formatter.format(frmdt);
Date todt=new Date(td);
String s2 = formatter.format(todt);
Date frmdate = sdf.parse(s1);
Date todate = sdf.parse(s2);
if(frmdate.compareTo(todate)<=0) {
//do your stuff
} else {
// do your stuff
}
}

http://developer.android.com/reference/java/util/Calendar.html
This should be allot easier to use for your purpose
Edit:
Methods you can use:
boolean after(Object calendar)
Returns whether the Date represented by this Calendar instance is after the Date represented by the parameter.
boolean before(Object calendar)
Returns whether the Date represented by this Calendar instance is before the Date represented by the parameter.

Maybe you can construct a Date form the String you get from DB, and then use today.before(daytime) to compare them.
Date daytime = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").parse(datetime.get(i));

How to create a Joda DateTime from a String

I have a String "26/09/2012 07:30:00" is it possible to create a new DateTime based on this String? Eventually i just want the time eg 7:30. I am going to format the DateTime by using DateFormatter eg
DateTimeFormatter fmt = DateTimeFormat.forPattern("k,m");
My question is how to construct a DT from the orginal String, i can format it once it's a DT.

Create an appropriate DateTimeFormatter for the input format, and then call DateTimeFormatter.parseLocalDateTime. (LocalDateTime is more appropriate than DateTime here, as your input data doesn't have a time zone or UTC offset indicator. You can convert to DateTime if you really need to, but it sound like you don't.)

Calendar c = Calendar.getInstance();
SimpleDateFormat df = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
String formattedDate = df.format(c.getTime());
Toast.makeText(this, formattedDate, Toast.LENGTH_SHORT).show();
// Now we display formattedDate value in TextView
TextView txtView = new TextView(this);
txtView.setText("Current Date and Time : "+formattedDate);
txtView.setGravity(Gravity.CENTER);
txtView.setTextSize(20);
setContentView(txtView);