<p>Is there an easy way within C# to check to see if a DateTime instance has been assigned a value or not?</p>

The only way of having a variable which hasn't been assigned a value in C# is for it to be a local variable - in which case at compile-time you can tell that it isn't definitely assigned by trying to read from it :)
I suspect you really want
```
Nullable<DateTime>
```
(or
```
DateTime?
```
with the C# syntactic sugar) - make it
```
null
```
to start with and then assign a normal
```
DateTime
```
value (which will be converted appropriately). Then you can just compare with
```
null
```
(or use the
```
HasValue
```
property) to see whether a "real" value has been set.