Blackberry - Set Time part of Date to the Start of a Day (12:00 AM)

Question

Hi,

As i am working on a reminder application, i need to show the reminder dialog whenever the set date has arrived for a particular data. I am using the following code to store the date.

 long now = System.currentTimeMillis();
 DateField dateField = new DateField("",now,DateField.DATE);
 long date = dateField.getDate();

For example, When the device Date & time is, 15 December, 2009 & 5:30:43 A.M, i am storing a data to Remind me on 18 December, 2009. When my app want to remind it, reminder comes on the same date as expected, but also in the same time only. i.e: 18 December, 2009, at 5:30:43 A.M. But i wanted to be shown as soon as 18 December, 2009 arrived when it is 12:00 A.M, i want to remind it.

I don't want to have time also in stored date. I just want to remind dialog as soon as the day arrived at 12:00 A.M.

I think when i store it, instead of 'System.currentTimeMillis', i should store with always '12:00 A.M" time in milliseconds?

Can someone please advice me to achieve it professionaly?

Thank you very much.

Answer 1

You can use math:

 public long getDayStartByMath(long date) {
  // 1000*60*60*24
  long fullDayPart = 86400000;
  return date - date % fullDayPart + (fullDayPart >> 1);
 }

Other way is to use Calendar:

 public long getDayStartByCalendar(long date) {
  Calendar c = Calendar.getInstance();
  c.setTime(new Date(date));
  c.set(Calendar.AM_PM, Calendar.AM);
  c.set(Calendar.HOUR, 12);
  c.set(Calendar.MINUTE, 0);
  c.set(Calendar.SECOND, 0);
  c.set(Calendar.MILLISECOND, 0);
  return c.getTime().getTime();
 }