in src/Serilog.Sinks.AzureDataExplorer/Durable/AzureDataExplorerPayloadReader.cs [49:64]
protected override void InitPayLoad(string filename)
{
m_payload = new List<LogEvent>();
var lastToken = filename.Split('-').Last();
// lastToken should be something like 20150218.log or 20150218_3.log now
if (!lastToken.ToLowerInvariant().EndsWith(".clef"))
{
throw new FormatException(string.Format(
"The file name '{0}' does not seem to follow the right file pattern - it must be named [whatever]-{{Date}}[_n].clef", Path.GetFileName(filename)));
}
var dateFormat = m_rollingInterval.GetFormat();
var dateString = lastToken.Substring(0, dateFormat.Length);
DateTime.ParseExact(dateString, dateFormat, CultureInfo.InvariantCulture);
}