add fallback parser when LD/JSON not found, use DOM parser

lib/parser-utils.js

@@ -0,0 +1,32 @@
+const dayjs = require('dayjs')
+
+// NOTE: Specific formatting for `ics` library
+const parseDates = (startDate, endDate) => {
+  const start = startDate ? [
+    startDate.year(),
+    startDate.month() + 1,
+    startDate.date(),
+    startDate.hour(),
+    startDate.minute(),
+  ] : (() => {
+    const now = dayjs()
+
+    return [
+      now.year(),
+      now.month() + 1,
+      now.date()
+    ]
+  })()
+  const diffInMinutes = endDate ?
+    endDate.diff(startDate, 'minutes') :
+    120
+
+  const duration = { minutes: diffInMinutes }
+
+  return {
+    start,
+    duration,
+  }
+}
+
+module.exports = { parseDates }