How to subtract the dates from the event date

Question

Here user will select the event Date...I know some suggestions are available for calendar based dates(current dates)....But my question is different because i have event date that will be select by user....I want to adjust reminder date from event date(particular date not for current date)...In my code i need to adjust 7 days(subtract 7 days) from the event date...I don't know how to do that...Please help me to find out the code

checkBox_aWeekBefore.setOnClickListener(new View.OnClickListener() {

                public void onClick(View v) {
                    if (((CheckBox) v).isChecked()) {
                        final int response = 3;
                        reminterDate=eventMO.getEventDate();
    //here i need to adjust eventDate and i need to adjust 7 days from EventDate and set that to reminder
                        List<EventReminderDaysMO> eventReminderDaysMOs = new ArrayList<>();

                        EventReminderDaysMO eventReminderDaysMO = new EventReminderDaysMO();
                        eventReminderDaysMO.setTypeId(3);
                        eventReminderDaysMO.setIsSelected(1);
                        eventReminderDaysMO.seteventReminderDate
                           (reminderdate);

                        eventReminderDaysMOs.add(eventReminderDaysMO);
                  eventMO.setEventReminderDaysMOs(eventReminderDaysMOs);

                        Toast.makeText(OccasionActivity.this,
                                "Checked", Toast.LENGTH_LONG).show();
                    }
                }
            });

This is my date formate

DateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy"); // Here use what format you use.
                       Date date1 = dateFormat.parse(eventDate);
                       DateFormat convertDate = new SimpleDateFormat(" yyyy-MM-dd hh:mm:ss");
                       eventDate = convertDate.format(date1);
                       eventMO.setEventDate(eventDate);

show more code about what's `reminterDate` format and how you declared it — cw fei, Sep 22 '15 at 06:40
in which format you want date and what is the format of reminterDate ? — KishuDroid, Sep 22 '15 at 06:43
possible duplicate of [How to subtract X days from a date using Java calendar?](http://stackoverflow.com/questions/212321/how-to-subtract-x-days-from-a-date-using-java-calendar) — Emil, Sep 22 '15 at 06:43
@ cw fei for this check box week before i need to set reminder date as week before i mean 7 days before....So i need to adjust the reminder date from the event date....After that i will pass that reminder date to data base — sathya. nagaraj19, Sep 22 '15 at 06:48

cw fei · Answer 1 · 2015-09-22T07:30:32.487

1

Use:

String date = "22-10-2015";
SimpleDateFormat format = new SimpleDateFormat("dd-mm-yyyy");
try {
        Date d = format.parse(date);
        Date dateBefore = new Date(d.getTime() - 7 * 24 * 3600 * 1000l ); 
        System.out.print(format.format(dateBefore)); // print 15-10-2015
    }
    catch(ParseException pe) { 

    }

Replace the date "22-10-2015" with your event date (according to your date's format), change the SimpleDateFormat's format to your existing date's format too. The 7 represents 7 days, change it to whatever you want.

edited Sep 22 '15 at 07:30

answered Sep 22 '15 at 06:54

cw fei

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I think this is for calendar (current dates)...I have event date here...i need to adjust reminder date from the event date...Event date will be select by user – sathya. nagaraj19 Sep 22 '15 at 06:57
that's why i need to know what's the event date format – cw fei Sep 22 '15 at 06:57
For example: i have a date picker to select a date...consider event date is 30-09-2015....In my check box week before i need to set reminder date 7 days before...So i need to adjust that to 27-09-2015....After that i will pass that to data base....Based on that reminder will be set – sathya. nagaraj19 Sep 22 '15 at 07:03
what @cwfei is asking whether the reminterDate is a string or date. – arun Sep 22 '15 at 07:05

arun · Answer 2 · 2015-09-22T08:01:23.223

1

Try this:

// If reminterDate is a string

DateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy"); // Here use what format you use.
Date date1 = dateFormat.parse(reminterDate);;
Calendar calendar = Calendar.getInstance(); 
calendar.setTime(date1 );
calendar.add(Calendar.DAY_OF_MONTH, -7);
date1 = calendar.getTime();

reminterDate = dateFormat.format(date1);

//Change this format
DateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy");
Date date1 = dateFormat.parse(eventDate);

eventDate = dateFormat.format(date1);
eventMO.setEventDate(eventDate);

edited Sep 22 '15 at 08:01

answered Sep 22 '15 at 07:01

arun

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DateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy"); // Here use what format you use. Date date1 = dateFormat.parse(eventDate); DateFormat convertDate = new SimpleDateFormat(" yyyy-MM-dd hh:mm:ss"); eventDate = convertDate.format(date1); eventMO.setEventDate(eventDate); – sathya. nagaraj19 Sep 22 '15 at 07:21
@sathya.nagaraj19 change the date format on your setEventDate – arun Sep 22 '15 at 08:03

How to subtract the dates from the event date

2 Answers2