asp.net mvc - In ModelState the Date format is not valid while editing Kedno grid -

i developing mvc application kedno grid. have model item properties:

public bool ispaid { get; set; } public nullable<datetime> paymentdate { get; set; } 

in kedno grid in view:

columns.bound(c => c.paymentdate).format("{0:dd-mmm-yyyy}"); 

when editing in grid , set ispaid false logic has setting paymentdate null.

for example have item paymentdate 22-sep-2016 , ispaid true.

after editing in kendo grid item setting ispaid false, , when click save changes, invoked method update in controller:

public actionresult update([datasourcerequest] datasourcerequest request, [bind(prefix = "models")]ienumerable<itemviewmodel> items) {         if (modelstate.isvalid)         {             //         } } 

but modelstate not valid: "the value '9/22/2016 12:00:00 am' not valid for...". if paymentdate 01-sep-2016, modelstate valid.

also, followed steps in globalization section.

in web.config:

<globalization uiculture="bg-bg" culture="bg-bg"></globalization> 

in controller:

protected override void initialize(requestcontext requestcontext) {     thread.currentthread.currentculture =         thread.currentthread.currentuiculture =             new cultureinfo(requestcontext.httpcontext.request.userlanguages[0]);      base.initialize(requestcontext); } 

in view:

@{     var culture = system.globalization.cultureinfo.currentculture.tostring(); }  <script src="@url.content("~/scripts/cultures/kendo.culture." + culture + ".min.js")"></script>  <script>     kendo.culture("@culture"); </script> 

any suggestions?

thanks lot!