Today we have this cases :

• Date of begining and date of end are defined : it display "From this day to this other day"
• Date of begining is defined : it display "This day"

We should test if date of begining = date of end to display the last case, then we could add 2 others cases :

• Date of begining is defined only : it display "From this day"
• Date of end is defined only : it display "Until this day"