This [line](https://github.com/SantanderMetGroup/bctool/blob/b3e00bb63fd39559127c28d779fd2fcfe97def4c/preprocessor.ESGF#L97) gives an error message: ``` date: option '--d' is ambiguous; possibilities: '--date' '--debug' Try 'date --help' for more information. ``` It works well when option `--d `is switched with `--date`.