Time library issue for NodeMCU in PlatformIO / VS Code on Windows 10

The warning is coming from what the Microsoft C/C++ Intellisense extensions thinks about the code, given the header files as and a list of activated macros. The “error” comes from a mismatch of macros regarding __STRICT_ANSI__, which should be undefined in order to have this extended functionality. The thread Identifier is undefined - setenv tzset is already exactly about that with a workaround.