remove support for weekly dates

(cherry picked from commit 976e2ae1)

src/DynareFlex.ll

@@ -71,7 +71,7 @@ string eofbuff;
 #define YY_USER_ACTION location_increment(yylloc, yytext);
 %}
 
-DATE -?[0-9]+([ya]|m([1-9]|1[0-2])|q[1-4]|w([1-9]{1}|[1-4][0-9]|5[0-2]))
+DATE -?[0-9]+([ya]|m([1-9]|1[0-2])|q[1-4])
 
 %%
  /* Code put at the beginning of yylex() */

src/Statement.cc

 /*
- * Copyright © 2006-2019 Dynare Team
+ * Copyright © 2006-2020 Dynare Team
  *
  * This file is part of Dynare.
  *
@@ -53,7 +53,7 @@ void
 NativeStatement::writeOutput(ostream &output, const string &basename, bool minimal_workspace) const
 {
   using namespace boost::xpressive;
-  string date_regex = R"((-?\d+([YyAa]|[Mm]([1-9]|1[0-2])|[Qq][1-4]|[Ww]([1-9]{1}|[1-4]\d|5[0-2]))))";
+  string date_regex = R"((-?\d+([YyAa]|[Mm]([1-9]|1[0-2])|[Qq][1-4])))";
   sregex regex_lookbehind = sregex::compile(R"((?<!\$|\d|[a-zA-Z_]|\'))" + date_regex);
   sregex regex_dollar = sregex::compile(R"((\$))"+date_regex);