feat: add implementation for day slot

src/lib/slots/DaySlot.ts

@@ -0,0 +1,58 @@
+import BaseSlot from "./BaseSlot";
+
+class DaySlot extends BaseSlot {
+  constructor() {
+    // Days are from 1 to 31 inclusive, so maximumValue is 32 to accommodate the offset
+    super(32);
+  }
+
+  override addSingle(value: number) {
+    this.checkNotZero(value);
+    return super.addSingle(value - 1);
+  }
+
+  override addRange(start: number, end: number) {
+    this.checkNotZero(start, end);
+    return super.addRange(start - 1, end - 1);
+  }
+
+  override addStep(step: number, start = 1) {
+    this.checkNotZero(start);
+    return super.addStep(step, start - 1);
+  }
+
+  override removeSingle(value: number) {
+    this.checkNotZero(value);
+    return super.removeSingle(value - 1);
+  }
+
+  override removeRange(start: number, end: number) {
+    this.checkNotZero(start, end);
+    return super.removeRange(start - 1, end - 1);
+  }
+
+  override removeStep(step: number, start = 1) {
+    this.checkNotZero(start);
+    return super.removeStep(step, start - 1);
+  }
+
+  override toString() {
+    let output = super.toString();
+
+    if (output === "*") return output;
+    else if (output.startsWith("0-1,")) return output.replace("0-1,", "1,");
+    else if (output.startsWith("0-")) return output.replace("0-", "1-");
+    else if (output.startsWith("0,")) return output.replace("0,", "1,");
+    else return output;
+  }
+
+  private checkNotZero(...values: number[]) {
+    values.forEach((value) => {
+      if (value === 0) {
+        throw new Error(`Value ${value} is out of bounds.`);
+      }
+    });
+  }
+}
+
+export default DaySlot;