Adjust "future date" entry checking

src/server.js

@@ -182,6 +182,8 @@ server.get('/counter', (req, res) => {
 server.get('/stats', (req, res) => { // eslint-disable-line complexity
 	let requestedStats = {};
 	const firstStatDate = moment(Object.keys(statistics)[0]);
+	const latestStatDate = moment(Object.keys(statistics)[Object.keys(statistics).length - 1]);
+	// grab latest statistics entry from the object itself instead of just today's date to make sure the entry exists
 
 	if (req.query.from || req.query.to) {
 		if ((req.query.from && !dateRegex.test(req.query.from)) || (req.query.to && !dateRegex.test(req.query.to))) {
@@ -191,7 +193,7 @@ server.get('/stats', (req, res) => { // eslint-disable-line complexity
 		const to = req.query.to ? moment(req.query.to) : null;
 		const from = req.query.from ? moment(req.query.from) : null;
 
-		if (to && to.isAfter(moment()) || from && from.isAfter(moment())) {
+		if (to && to.isAfter(latestStatDate) || from && from.isAfter(latestStatDate)) {
 			return res.status(400).json({ code: 400, name: 'Invalid timespan', message: 'Dates can not be in the future.' });
 		}
 
@@ -211,8 +213,6 @@ server.get('/stats', (req, res) => { // eslint-disable-line complexity
 		}
 	}
 	else {
-		const latestStatDate = moment(); // today
-
 		requestedStats = filterStats(firstStatDate, latestStatDate);
 	}