diff --git a/ifc/Cargo.toml b/ifc/Cargo.toml
index 0da100b..30cd94d 100644
--- a/ifc/Cargo.toml
+++ b/ifc/Cargo.toml
@@ -7,7 +7,6 @@ edition = "2018"
 keywords = ["date", "time", "calendar"]
 categories = ["date-and-time"]
 license = "GPL-3.0-only"
-license-file = "../COPYING"
 
 [dependencies]
 chrono =        { version = "0.4" }
diff --git a/ifc/src/lib.rs b/ifc/src/lib.rs
index 5ede0c0..83b5719 100644
--- a/ifc/src/lib.rs
+++ b/ifc/src/lib.rs
@@ -141,9 +141,7 @@ impl IFC {
     }
 
     pub fn ymd(year: i32, month: u8, day: u8) -> Result<Self, Error> {
-        if month < 1 || month > 13 {
-            Err(Error::InvalidDate)
-        } else if day < 1 || day > 28 {
+        if !(1..=13).contains(&month) || !(1..=28).contains(&day) {
             Err(Error::InvalidDate)
         } else {
             Ok(Self::Day(Day { year, month, day }))
@@ -248,12 +246,12 @@ impl From<chrono::NaiveDate> for IFC {
             if is_leap_year(date.year())
                 && date > NaiveDate::from_ymd_opt(date.year(), 6, 17).unwrap()
             {
-                days = days - 1;
+                days -= 1;
             }
             let mut month: u8 = (days / 28).try_into().unwrap();
             let mut day: u8 = (days % 28).try_into().unwrap();
             if day == 0 {
-                month = month - 1;
+                month -= 1;
                 day = 28;
             }
             Self::Day(Day {