Fix Issues in Date, Calendar, Streak, Timer, and Task Manager Code

[Amansingh0807]

The current code has the following issues that need to be fixed:

- Date & Time Display: Minor formatting inconsistencies.
- Calendar: Incorrect highlighting of the current day when reloading.
- Streak Counter: Streak logic breaks when toggling the checkbox multiple times.
- Timer: Timer doesn’t reset correctly after goal time updates.
- Task Manager: Tasks don’t persist UI state correctly after page reloads.

Expected Behavior:

• Accurate date & time formatting.
• Calendar highlights the correct date consistently.
• Streak increments only once per day.
• Timer resets properly when goal time changes.
• Task status remains consistent after page reloads.

[github-actions]

Thank you for raising this issue! We'll look into it as soon as possible. Please ensure that the issue is not duplicate, and you read CONTRIBUTING.md carefully. Your contributions are highly appreciated! 😊