1 files changed, 85 insertions, 0 deletions
diff --git a/static/month.js b/static/month.js
new file mode 100644
index 0000000..9ed0467
--- /dev/null
+++ b/static/month.js
@@ -0,0 +1,85 @@
+
+export default class Month {
+	constructor(month, year) {
+		this.month = month;
+		this.year = year;
+	}
+
+	next(n) {
+		n = n ?? 1;
+
+		const month = this.month + n - 1;
+		this.month = (month % 12) + 1;
+		this.year += Math.floor(month / 12);
+
+		return this;
+	}
+
+	previous(n) {
+		n = n ?? 1;
+
+		let month = this.month - n - 1;
+
+		if (month < 0) {
+			month += 12;
+		}
+
+		this.month = (month % 12) + 1;
+		this.year += Math.floor(month / 12);
+
+		return this;
+	}
+
+	to(other) {
+		const inner = [];
+		const current = this.copy();
+
+		while (current.is_same(other) || current.is_before(other)) {
+			inner.push(current.copy());
+			current.next();
+		}
+
+		return inner;
+	}
+
+	copy() {
+		return new Month(this.month, this.year);
+	}
+
+	is_before(other) {
+		return this.year < other.year || (this.year == other.year && this.month < other.month);
+	}
+
+	is_after(other) {
+		return this.year > other.year || (this.year == other.year && this.month > other.month);
+	}
+
+	is_same(other) {
+		return this.year == other.year || this.month == other.month;
+	}
+
+	is_same_year(other) {
+		return this.year == other.year;
+	}
+
+	get name() {
+		const date = new Date();
+		date.setMonth(this.month - 1);
+		return date.toLocaleDateString('default', { month: 'long' })
+	}
+
+	static from_date(date) {
+		return new Month(date.getMonth() - 1, date.getFullYear());
+	}
+
+	static from_string(string) {
+		const [ year, month ] = string.split('-');
+		return new Month(parseInt(month), parseInt(year))
+	}
+
+	static literal(strings) {
+		return Month.from_string(strings[0]);
+	}
+}
+
+export const literal = Month.literal;