Replace Date class usage

[php-coder]

We should use new datetime API from Java8 instead (LocalDateTime).

Depends on:

• [ ] #930
• [ ] #931
• [ ] #933
• [ ] #1032
• [ ] #1033
• [ ] #1622

[php-coder]

These links may be useful:

• http://java.amitph.com/2013/03/introduction-to-new-java-date-and-time.html
• http://java.amitph.com/2013/04/introduction-to-jsr-310-part-2-overview.html
• http://java.amitph.com/2014/01/introduction-to-jsr-310-part-3-overview_25.html

[0pdd]

@php-coder the puzzle #930 is still not solved.

[0pdd]

@php-coder 2 puzzles #930, #931 are still not solved.

[0pdd]

@php-coder 3 puzzles #930, #931, #933 are still not solved.

[0pdd]

@php-coder 5 puzzles #1032, #1033, #930, #931, #933 are still not solved.

[php-coder]

Could be useful: https://github.com/thymeleaf/thymeleaf-extras-java8time