DataLogger

how do I get the file name of my datalogger to be today's date and update it every day ?

I would use the Time library to keep track of date/time, and format a C-string (character array) with the date, to use as the file name.

Example of formatting a date into a six character string:

char date_string[7]; //leave room for zero terminator
int day=15;
int month=10;
int year=2018;
snprintf(date_string,6,"%02d%02d%02d",day,month,year-2000);
Serial.print(date_string); //prints 151018

Ok!
Thanks