Same issue than trantor::Date https://github.com/an-tao/trantor/pull/140

Hi,

To take DST into account, mktime need tm.is_dst to be set to -1: https://en.cppreference.com/cpp/chrono/c/mktime Notes If the std::tm object was obtained from std::get_time or the POSIX [strptime](https://pubs.opengroup.org/onlinepubs/009695399/functions/strptime.html), the value of tm_isdst is indeterminate, and needs to be set explicitly before calling mktime.

The same code from trantor::Date need to be set in src/drogon_ctl/templates/model_cc.csp:

$$<<"            struct tm stm;\n";
$$<<"            memset(&stm,0,sizeof(stm));\n";
$$<<"            strptime(daysStr.c_str(),\"%Y-%m-%d\",&stm);\n";
$$<<"            time_t t = mktime(&stm);\n";

Templates need to be change into:

$$<<"            struct tm stm;\n";
$$<<"            memset(&stm,0,sizeof(stm));\n";
$$<<"            stm.is_dst = -1;\n";
$$<<"            strptime(daysStr.c_str(),\"%Y-%m-%d\",&stm);\n";
$$<<"            time_t t = mktime(&stm);\n";

thanks !