# .NET Core Mercury, just "Date" is not valid?
**URL:** https://talk.remobjects.com/t/net-core-mercury-just-date-is-not-valid/26267
**Category:** Water
**Tags:** mercury
**Created:** [March 1, 2022, 2:48pm UTC](https://talk.remobjects.com/t/net-core-mercury-just-date-is-not-valid/26267 "2022-03-01T14:48:44Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@avonelle](https://talk.remobjects.com/u/avonelle)
#### Post date: [March 1, 2022, 2:48pm UTC](https://talk.remobjects.com/t/net-core-mercury-just-date-is-not-valid/26267/1 "2022-03-01T14:48:44Z")
Version 11.0.0.2717 in Mercury (I’ve only tried this in Water.)
In classic [VB.NET](http://VB.NET), I can define a property or variable as just Date instead of DateTime, and it compiles and runs fine. This also seems to work in a standard VB .NET Core project in Visual Studio.
But in my test [ASP.NET](http://ASP.NET) Core Mercury project, I am getting an Unknown Type error:
Not a big deal if this isn’t going to be supported going forward, because as near as I can tell it still treats it as a DateTime. Even the tooltip in Visual Studio shows it as a DateTime.
But I’m thinking if I had existing [VB.NET](http://VB.NET) code I was moving to Mercury, it might be kind of a pain.
I haven’t tested any other scenarios (like standard .NET).
–Avonelle
---
### Author:  [@mh](https://talk.remobjects.com/u/mh)
#### Post date: [March 1, 2022, 4:56pm UTC](https://talk.remobjects.com/t/net-core-mercury-just-date-is-not-valid/26267/2 "2022-03-01T16:56:25Z")
Hmm. pretty sure we had an alias to DateTime. let me check…
---
### Author:  [@mh](https://talk.remobjects.com/u/mh)
#### Post date: [March 1, 2022, 4:57pm UTC](https://talk.remobjects.com/t/net-core-mercury-just-date-is-not-valid/26267/3 "2022-03-01T16:57:41Z")
```auto
Module Program
Sub Main(args as String())
writeLn("The magic happens here.")
Dim X As Date
writeLn($"x {X}")
End Sub
End Module
```
this compiles fine for me in a new project, what could I be missing?
---
### Author:  [@avonelle](https://talk.remobjects.com/u/avonelle)
#### Post date: [March 1, 2022, 5:02pm UTC](https://talk.remobjects.com/t/net-core-mercury-just-date-is-not-valid/26267/4 "2022-03-01T17:02:39Z")
> [@mh](#):
>
> this compiles fine for me in a new project, what could I be missing?
Hmmmm…You are right, works fine for me with a .NET Classic console app and a .NET Core console app.
Let me see if I can figure out what the difference is…
–Avonelle
---
### Author:  [@avonelle](https://talk.remobjects.com/u/avonelle)
#### Post date: [March 1, 2022, 5:11pm UTC](https://talk.remobjects.com/t/net-core-mercury-just-date-is-not-valid/26267/5 "2022-03-01T17:11:35Z")
I think it is something specific to [ASP.NET](http://ASP.NET) Core projects. Adding a simple variable declaration of Date fails for both the “[ASP.NET](http://ASP.NET) Core MVC/Razor-based Web application” and “[ASP.NET](http://ASP.NET) Core Empty Web Application” project templates. But it compiled fine for a classic Windows app.
FYI: I also see that “Date” doesn’t show up in the CC list in my test projects for [ASP.NET](http://ASP.NET) Core but it does in the classic Windows app.
–Avonelle
---
### Author:  [@mh](https://talk.remobjects.com/u/mh)
#### Post date: [March 1, 2022, 7:12pm UTC](https://talk.remobjects.com/t/net-core-mercury-just-date-is-not-valid/26267/6 "2022-03-01T19:12:10Z")
Hmm, it looks like the template misses a reference to Mercury.dll. Adding that fixes it. I’ll fix the templates.
---
### Author:  [@avonelle](https://talk.remobjects.com/u/avonelle)
#### Post date: [March 1, 2022, 7:39pm UTC](https://talk.remobjects.com/t/net-core-mercury-just-date-is-not-valid/26267/7 "2022-03-01T19:39:38Z")
Excellent. Thanks!
–Avonelle