Nothing good :-(

(i left your row culture force in user.config )

Always the same, and just press [now] button in the calendar interface it get the right value with the colon separator.

Here the "System log" i've clean the log and this the result when i press the [save] button with the defaul data value in the filed (dot separator.)

2012-09-08 11:14:40,618 ERROR 79.30.46.199 - it-IT - /siteit/Blog/EditPost.aspx?mid=22&pageid=6 - mojoPortal.Web.mojoBasePage - 79.30.46.199-it-IT - /siteit/Blog/EditPost.aspx?mid=22&pageid=6
System.FormatException: String was not recognized as a valid DateTime.
at System.DateTimeParse.Parse(String s, DateTimeFormatInfo dtfi, DateTimeStyles styles)
at mojoPortal.Web.BlogUI.BlogEdit.Save()
at mojoPortal.Web.BlogUI.BlogEdit.btnUpdate_Click(Object sender, EventArgs e)
at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
2012-09-08 11:14:40,618 ERROR 79.30.46.199 - it-IT - /siteit/Blog/EditPost.aspx?mid=22&pageid=6 - mojoPortal.Web.Global -  Referrer(http://www.************.it/siteit/Blog/EditPost.aspx?mid=22&pageid=6) useragent Mozilla/5.0 (Windows NT 6.1; rv:15.0) Gecko/20100101 Firefox/15.0
System.FormatException: String was not recognized as a valid DateTime.
at System.DateTimeParse.Parse(String s, DateTimeFormatInfo dtfi, DateTimeStyles styles)
at mojoPortal.Web.BlogUI.BlogEdit.Save()
at mojoPortal.Web.BlogUI.BlogEdit.btnUpdate_Click(Object sender, EventArgs e)
at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

I worked hard, and I have achieved important results, I try to motivate you!:

i fix the error and fill in the field the "colon" if in:
web.config
(<globalization Culture="en-US" uiCulture="en-US" .../>) so forced in en and not as it was by default: "auto:en-US"

Plus: for have the user interface in Italian I tried:
(<globalization culture="en-US" uiCulture="auto:en-US" ..../>) It works!

BUT I do not know (culture = "en-US" forced) what is involved in the rest of the site.
for example, startdate field now works, however, reverses the month with the day as it is right in en but not HERE! (and we don't use the AM/PM 09/10/2012 2:13 PM, my users to be able to tell that the day the month should be reversed? )

I would be happier to solve olso this, can you help me even a little? I will try to get you at least 2 beers!

OK!, thanks but I'll have to set them mixed, because otherwise it does not work, there will be a bug in some script because as written above, if i put "site1culture = it-IT" does not work and it must be mixed:

The only way it works: (a bad work-around)

<add key="site1culture" value="en-US" />
<add key="site1uiculture" value="it-IT" />

(Attention! because the dates will be reversed. (the months will be before the day, English format !!!)