Dates Mess Up

Hi there, have got two Excel questions here:

1. Unless i key in the date specifically, Excel automatically assumes year 1990. My question is, how do i make Excel recognise the year and adds up sequentially? For example, if the column above says 1 June 2010, when i type 1 Jan in a column afterwards i want it to be able to recognise it as 1 Jan 2011 for that specific row?

2. How do i make the entire spreadsheet allow only date entries for weekdays? Right now im hiding the weekend dates, but asides from this method, is there any other way around it? (asides from validation rule)

Thanks!

Hello Ram'
Please attach a dummy sheet with an example of what you want as a result.
Regards
Peter