How do I get the time an hour from now for my 12 hour time format in string?

Question

I am planning to add an hour to the current time, which I have converted into a 12 hour format. Just not sure how to go about it. I want to keep mins the same, just want to add an hour, say the time is 11:59am -> I would like to show 12:59pm, or if the time is 5:20, I would like to show 6:20 and so on. Here's my code so far :

if (mDate.get(Calendar.AM_PM) == Calendar.AM)
            am_pm = "AM";
        else if (mDate.get(Calendar.AM_PM) == Calendar.PM)
            am_pm = "PM";


        String strHrsToShow = (mDate.get(Calendar.HOUR) == 0) ? "12" : mDate.get(Calendar.HOUR) + "";
        String strMinsToShow = (mDate.get(Calendar.MINUTE)) < 10 ? "0" + mDate.get(Calendar.MINUTE) : "" + mDate.get(Calendar.MINUTE);

        mRegisterGuestStartTime.setText(String.format("%s:%s %s", strHrsToShow, strMinsToShow, am_pm));

Any ideas how to go about it? thanks in advance!

Answer 1

mDate is a Calendar object I assume. If yes, why don't you use Calendar.add(Calendar.HOUR, 1)? Doing it in String manipulation way lost the precision of the date/time value. You can use SimpleDateFormat to format the Calendar afterward

    // add an hour to the date
    mDate.add(Calendar.HOUR, 1);

    // prepare datetime formatter, sample output: "11:35 AM"
    SimpleDateFormat timeFormat = new SimpleDateFormat("HH:mm a");
    mRegisterGuestStartTime.setText(timeFormat.format(mDate.getTime()));