DateTimeFormatter Playground

Build a pattern, see the output. Or take a formatted string and parse it back into a LocalDate. Two directions, one tool.

DateTimeFormatter lives in java.time.format. You build one with DateTimeFormatter.ofPattern("...") using letter codes below, then pass it to format() to output a string — or to parse() to turn a string into a date.

Playground

Date: Time:

Pattern:

Try a preset:

Output string

—

LocalDateTime dt = LocalDateTime.parse("—");
DateTimeFormatter fmt = DateTimeFormatter.ofPattern("—");
String out = dt.format(fmt);  // → "—"
    

Input string: Pattern:

Try a preset (input & pattern together):

Parsed LocalDate

—

String input = "—";
DateTimeFormatter fmt = DateTimeFormatter.ofPattern("—");
LocalDate d = LocalDate.parse(input, fmt);  // → —
    

Heads-up: if the input doesn't match the pattern, Java throws DateTimeParseException. Bad month, wrong separator, extra text — all throw.

Tip: the letters are case-sensitive. MM means month, mm means minute — don't mix them up (this is the #1 date format bug).

DateTimeFormatter Playground

Pattern letters — reference