Rewrite function to get current day and address comments

README.md

@@ -161,7 +161,7 @@ cargo read <day>
 
 ### Scaffold, download and read in one go
 
-This command runs `cargo scaffold`, `cargo download` and `cargo read` for the current day.
+This command runs `cargo scaffold --download`, and `cargo read` for the current day.
 
 ```sh
 # example: `cargo today` on December 1st

src/main.rs

@@ -1,6 +1,10 @@
-use advent_of_code::template::commands::{all, download, read, scaffold, solve};
+use std::process;
+
+use advent_of_code::template::{
+    commands::{all, download, read, scaffold, solve},
+    Day,
+};
 use args::{parse, AppArguments};
-use chrono::Local;
 
 mod args {
     use advent_of_code::template::Day;
@@ -100,13 +104,19 @@ fn main() {
                 submit,
             } => solve::handle(day, release, time, dhat, submit),
             AppArguments::Today => {
-                match Local::now().try_into() {
-                    Ok(day) => {
+                match Day::today() {
+                    Some(day) => {
                         scaffold::handle(day);
                         download::handle(day);
                         read::handle(day)
                     }
-                    Err(e) => println!("{e}"),
+                    None => {
+                        eprintln!(
+                            "`today` command can only be run between the 1st and \
+                            the 25th of december. Please use `scaffold` with a specific day."
+                        );
+                        process::exit(1)
+                    }
                 };
             }
         },

src/template/day.rs

@@ -1,4 +1,4 @@
-use chrono::{DateTime, Datelike, Local};
+use chrono::{Datelike, Local};
 use std::error::Error;
 use std::fmt::Display;
 use std::str::FromStr;
@@ -38,15 +38,15 @@ impl Day {
     }
 }
 
-impl TryFrom<DateTime<Local>> for Day {
-    type Error = &'static str;
-
-    fn try_from(date: DateTime<Local>) -> Result<Self, Self::Error> {
-        let day = date.day();
-        if date.month() != 12 || day == 0 || day > 25 {
-            return Err("Cannot run this command on a day outside of the Advent of Code days.");
+impl Day {
+    /// Returns the current day if it's between the 1st and the 25th of december, `None` otherwise.
+    pub fn today() -> Option<Self> {
+        let today = Local::now();
+        if today.month() == 12 && today.day() <= 25 {
+            Self::new(u8::try_from(today.day()).ok()?)
+        } else {
+            None
         }
-        Ok(Self(day as u8))
     }
 }