public static string GetRecurrenceExpression()
{
var startDate = new DateTime(2013, 3, 1);
var recursUntil = new DateTime(2013, 3, 3);
var duration = TimeSpan.FromMinutes(30);
var maxOccurrences = 0;
var interval = 1;
IRecurrenceDescriptor dailyDescriptor = null;
var rrBuilder = new RecurrenceRuleBuilder();
var dailyExpression = rrBuilder.CreateDailyRecurrenceExpression(startDate, duration, recursUntil, maxOccurrences, interval);
//if isParsed returns true the iCal daily recurrence expression is parsed
var isParsed = rrBuilder.TryParseRecurrenceExpression(dailyExpression, out dailyDescriptor);
string dailyExpressionReParsed = rrBuilder.GetRecurrenceExpression(dailyDescriptor);
return dailyExpression;
}