I have never used JodaTime before, but answering this question, How to get ordinal Weekdays in a Month.
I tried it and came up with this ugly code to unset all fields below day:
DateTime startOfMonth =
input.withDayOfMonth(1)
.withHourOfDay(0) // there
.withMinuteOfHour(0) // has got to
.withSecondOfMinute(0) // be a shorter way
.withMillisOfSecond(0); // to do this
Where the Commons / Lang equivalent using DateUtils would be
Date startOfMonth = DateUtils.truncate(input, Calendar.MONTH);
What's the preferred idiom to do that in JodaTime?
You can use roundFloorCopy() to mimic DateUtils.truncate
Date truncateMonth = DateUtils.truncate(input, Calendar.MONTH);
-> DateTime truncateMonth = input.dayOfMonth().roundFloorCopy();
Date truncateMinute = DateUtils.truncate(input, Calendar.MINUTE);
-> DateTime truncateMinute = input.minuteOfDay().roundFloorCopy();
Date truncateHourOfDay = DateUtils.truncate(input, Calendar.HOUR_OF_DAY);
-> DateTime truncateHourOfDay = input.hourOfDay().roundFloorCopy()