diff --git a/ml_date.cpp b/ml_date.cpp
index e6ff561..834afd3 100644
--- a/ml_date.cpp
+++ b/ml_date.cpp
@@ -23,15 +23,19 @@ std::string date_to_string(const long datetime, const std::string format) {
     return "invalid argument";
 }
 
+std::istringstream string_to_date_in_ss;
 long string_to_date(const std::string &datestr, const std::string &format) {
 	// format for example "%d.%m.%Y";
 
-	std::istringstream in{datestr.c_str()};
+	string_to_date_in_ss.clear();
+	string_to_date_in_ss.str(datestr);
+
 	date::sys_seconds tp;
-	in >> date::parse(format, tp);
+	date::from_stream(string_to_date_in_ss, format.c_str(), tp);
 	return tp.time_since_epoch().count();
 }
 
+
 long add_to_date(const long datetime, const long quantity, const std::string &part) {
 	// part is one of 'year', 'month', 'day', 'hour', 'minute' or 'second'