Home DateTimeFormatter – java.lang.IllegalArgumentException: Too many pattern letters: a

Questions

DateTimeFormatter – java.lang.IllegalArgumentException: Too many pattern letters: a

April 5, 2022

I have the following line in my java code where I am trying to format a date string

 ZonedDateTime zonedDateTime= ZonedDateTime.ofInstant(instant, tz);
 DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm aa");

 return zonedDateTime.format(formatter);

At line 2 , I am getting this error:

java.lang.IllegalArgumentException: Too many pattern letters: a
at java.time.format.DateTimeFormatterBuilder.parseField(DateTimeFormatterBuilder.java:1774)

How can I create a format string for DateTimeFormatter.ofPattern that will give e.g:

2023-04-21 7.00pm

>Solution :

Use one `a`

As the error describes, you have used to many a character codes.

👉 Change aa to a.

You may have been thinking of two letters for AM and PM. But actually, other text might appear instead. The text generated by a depends on the human language and cultural norms used during localization. You specify the language and norms by way of a Locale. If omitted, your JVM’s current default locale is implicitly applied.