fix: respect time, not just dates

src/index.js

@@ -1,4 +1,4 @@
-module.exports = exports = ({
+const nextMonthly = ({
   from = new Date('0000-01-31T00:00:00.000Z'),
   now = Date.now(),
 } = {}) => {
@@ -27,5 +27,10 @@ module.exports = exports = ({
     _from.getUTCMilliseconds(),
   ))
 
+  // if nextDate is on the same date as _now and has already passed
+  if (nextDate <= _now) return nextMonthly({ from, now: nextDate.valueOf() + (86400 * 1000) })
+
   return nextDate
 }
+
+module.exports = exports = nextMonthly

src/index.spec.js

@@ -48,6 +48,20 @@ it('returns 29th on leap year when target is 31st', () => {
   expect(output.toJSON()).toBe('2000-02-29T00:00:00.000Z')
 })
 
+it('respects time, not just dates', () => {
+  // one millisecond after - yields next month
+  expect(nextMonthly({
+    from: new Date('1990-01-07T01:29:03.999Z'),
+    now: new Date('2023-01-07T01:29:04.000Z'),
+  }).toJSON()).toBe('2023-02-07T01:29:03.999Z')
+
+  // a few ms before - yields today
+  expect(nextMonthly({
+    from: new Date('1990-01-07T01:29:03.999Z'),
+    now: new Date('2023-01-07T01:29:03.888Z'),
+  }).toJSON()).toBe('2023-01-07T01:29:03.999Z')
+})
+
 it('behaves like README', () => {
   const nextBillingDate = nextMonthly({
     from: new Date('1990-01-07T01:29:03.999Z'),