I have two date/time fields on my doctype that almost work correctly on my form. I added the appropriate javascripts as shown below, but only the date picker displays, the time sliders are missing.

HtmlLink css = new HtmlLink();
css.Href = "/css/Doc2Form.css";
css.Attributes["rel"] = "stylesheet";
css.Attributes["type"] = "text/css";
Page.Header.Controls.Add(css);

css = new HtmlLink();
css.Href = "/umbraco_client/DateTimePicker/datetimepicker.css";
css.Attributes["rel"] = "stylesheet";
css.Attributes["type"] = "text/css";
Page.Header.Controls.Add(css);

HtmlGenericControl jscript = new HtmlGenericControl();
jscript.TagName = "script";
jscript.Attributes.Add("type", "text/javascript");
jscript.Attributes.Add("src", "/umbraco_client/ui/jqueryui.js");
Page.Header.Controls.Add(jscript);

jscript = new HtmlGenericControl();
jscript.TagName = "script";
jscript.Attributes.Add("type", "text/javascript");
jscript.Attributes.Add("src", "/umbraco_client/DateTimePicker/umbDateTimePicker.js");
Page.Header.Controls.Add(jscript);