controls

What is the best Date Entry/Selection Widget You've Ever Seen? What Makes it the best? Same question for Time Entry/Selection.

I'm putting together a design standard for the best possible widgets for date and time entry/selection. Anyone have examples that fit all or at least some of these requirements? I understanding that this is contextual and there is no one size fits all):

1. Supports multiple input methods – mouse (click and scroll), keyboard (explicit values as well as arrows, tabs, spacebar, enter) when the platform allows it.

Impossible data entry control

In early interaction design sessions, my business partners are asking
for the following: I don't believe it exists.

1. Web Page with simple template allowing data entry.
2. Data must be able to be "pasted" in from other sources (most
likely from a spreadsheet)
3. Data will be variable (1 - N rows)
4. Data format will need to be validated on submission. (Two columns
of data will be allowed, one an identifier and the second a currency
amount)

I'm thinking of GDocs spreadsheet type functionality - but am not
aware of that type of control being commonly available.