Personal Happiness Index

I always wanting to find a way to measure happiness of an individual. After some brain storming, I have come out with a simple formula shown below.

First, we must list out all the events that you will do for a month.

For example.
Working
Entertaining
Sleeping
Relaxing

Second, for each event, we have to state the value for the degree of happiness. The value is range between -1 to 1.
-1 means you are very unhappy when doing the event.
-0.5, you are unhappy when doing the event.
0 mean you are neutral when doing the event.
0.5 mean you are happy when doing the event.
1 mean you are very happy when doing the event.

For example:
Working (-0.2)
Entertaining (0.5)
Sleeping (0.3) (Value can be negative, if you always cannot sleep well due to some reasons)
Relaxing (0.5)

Third, we must know the total duration in minutes for each event done per month.
For example:
Working (14400min)
Entertaining (7200min)
Sleeping (14400min)
Relaxing (7200min)

Four, we will use the below formula to find out the happiness in each Event.
Happiness in each Event = Degree of Happiness X Time Duration

Working (-0.2) x (14400) = -2880
Entertaining (0.5) x (7200) = 3600
Sleeping (0.3) x(14400) = 4320
Relaxing (0.5) x (7200) = 3600

Lastly we will use the below formula to calculate the Personal Happiness Index.
Personal Happiness Index = sum of happiness in all event / 43200 min.

If the index is -1, mean you are very unhappy.
If the index is 0, mean you are neutral
If the index is 1, mean you are very happy

For example:
Happiness Index = (-2880 + 3600 + 4320 + 3600)/43200 = 0.2
0.2 means slightly happy.