Querying with nHibernate where todays date is between publishDate and Expiry date - nhibernate

Question

I am trying to figure out how to best query in NHibernate so that the returned results are between for entries where todays time is >= PublishDateTime and <=ExpiryDateTime
The expiry date can be null so I need to allow for that. I found a couple of examples here and here but they seem to work in a different way and accept 2 values and compare to one DB field. I want the other way wrong really.
Query so far:
var query = _session.CreateCriteria<Message>()
.AddOrder(Order.Desc("PublishedDateTime"))
.List<Message>();
return query;
Any suggestions would be greatly received!

Answer 1

Easiest Linq query:
return _session.Query<Message>()
.Where(m => DateTime.Today >= m.PublishDateTime &&
(m.ExpiryDateTime == null ||
DateTime.Now <= m.ExpiryDateTime)
.OrderByDescending(m => m.PublishDateTime)
.ToList();
Criteria:
return _session.CreateCriteria<Message>()
.Add(Restrictions.Le("PublishedDateTime", DateTime.Today) &
(Restrictions.IsNull("ExpiryDateTime") |
Restrictions.Ge("ExpiryDateTime",
DateTime.Now)))
.AddOrder(Order.Desc("PublishedDateTime"))
.List<Message>();

Answer 2

In c# :
var formato = "dd/MM/yyyy h:mm:ss";
var sDesde = DateTime.Now.ToString("dd/MM/yyyy") + " 0:00:00";
var sHasta = DateTime.Now.ToString("dd/MM/yyyy h:mm:ss");
Viaje vDesde = new Viaje { Viajefecha = DateTime.ParseExact(sDesde, formato , null) };
Viaje vHasta = new Viaje { Viajefecha = DateTime.ParseExact(sHasta, formato, null) };
StringWriter strWriter = new StringWriter();
var resultado = cp.sesion.CreateCriteria<Viaje>().Add(Expression.Between("Viajefecha", vDesde.Viajefecha, vHasta.Viajefecha)).AddOrder(Order.Asc("Viajefecha")).List<Viaje>();