$daysOfWeek:

1 => Sunday

2 => Monday

3 => Tuesday

4 => Wednesday

5 => Thursday

6 => Friday

7 => Saturday

$daysOfWeek Reversed:

7 => Saturday

6 => Friday

5 => Thursday

4 => Wednesday

3 => Tuesday

2 => Monday

1 => Sunday

$daysOfWeek Sorted Alphabetically:

6 => Friday

2 => Monday

7 => Saturday

1 => Sunday

5 => Thursday

3 => Tuesday

4 => Wednesday