feat: implement date handling and formatting

lib/utils.js

@@ -1,18 +1,46 @@
 'use strict';
 
+const prefixNumber = (n) => {
+	if (n < 10)
+		return `0${n}`;
+	return n.toString();
+};
+
+const date = {
+	getDateObject(d = Date.now()) {
+		const dateObject = new Date(d);
+		// eslint-disable-next-line no-restricted-globals
+		if (isNaN(dateObject))
+			throw new Error(`${d} is invalid date.`);
+		return dateObject;
+	},
+	toISODate(d = Date.now(), utc = true) {
+		const t = date.getDateObject(d);
+		if (utc)
+			return `${t.getUTCFullYear()}-${prefixNumber(t.getUTCMonth() + 1)}-${prefixNumber(t.getUTCDate())}`;
+		return `${t.getFullYear()}-${prefixNumber(t.getMonth() + 1)}-${prefixNumber(t.getDate())}`;
+	},
+	toISOTime(d = Date.now(), utc = true) {
+		const t = date.getDateObject(d);
+		if (utc)
+			return `${prefixNumber(t.getUTCHours())}:${prefixNumber(t.getUTCMinutes())}:${prefixNumber(t.getUTCSeconds())}`;
+		return `${prefixNumber(t.getHours())}:${prefixNumber(t.getMinutes())}:${prefixNumber(t.getSeconds())}`;
+	},
+};
+
 const dateRange = (start, end) => {
 	if (start && end)
 		return {
 			DateRange: {
-				Start: start,
+				Start: date.toISODate(start),
-				End: end,
+				End: date.toISODate(end),
 			},
 		};
 
 	return {};
 };
 
-
 module.exports = {
 	dateRange,
+	date,
 };