Snippet for getting timestamp in milliseconds for the present day with time taken as 00:00:00.

// Eg: ts for '2013-02-19'
public long getTsForToday() {
    Calendar cal = Calendar.getInstance();
    int year = cal.get(cal.YEAR);
    int month = cal.get(cal.MONTH);
    int date = cal.get(cal.DATE);
    cal.clear();
    cal.set(Calendar.YEAR, year);
    cal.set(Calendar.MONTH, month);
    cal.set(Calendar.DATE, date);
    return cal.getTimeInMillis();
}