Return furthest right value which is greater than zero

Hi,

(The attached picture should help explain the text, ignore cells in red, yellow is what I'm after).

I've inherited a timesheet worksheet, which has the names of employees in the rows, dates in the columns and the number of hours worked as the data.

I have a column entitled 'Last Day' where I need to enter the last day each resource worked, which corresponds to the value furthest right which is greater than zero. Is there a quick way of doing this? Please bear in mind I have limited vba experience.

There are a few quirks to this too:
1. weekends are on the time sheet which are blank for most people whereas others have entered values
2. sometime people have entered zero until they started work, for others the first value is the first day they worked

Any help much appreciated!