C#. Validation of date pattern

Question

In my application user can specify the pattern for dates by entering it in the textbox. This pattern is used for logging messages. For example, if user specify 'dd-MM' then in the log file he could see following:

[12-06] Some message...
[02-09] Some message 2...

How to validate this pattern? How to protect entering wrong patterns?

Answer 1

The easiest way is to just try and parse the date.

DateTime someDate;

// Valid will be false if it could not parse the date
bool valid = DateTime.TryParse(yourFormat, out someDate);

Answer 2

Regular Expressions will probably be a good choice.

Answer 3

You can take a look at Regular Expressions or else, at this question