diff --git a/src/Logic/Web/LinkedDataLoader.ts b/src/Logic/Web/LinkedDataLoader.ts
index 8c477677e..080073eda 100644
--- a/src/Logic/Web/LinkedDataLoader.ts
+++ b/src/Logic/Web/LinkedDataLoader.ts
@@ -158,7 +158,10 @@ export default class LinkedDataLoader {
             openingHoursSpecification,
             <any>LinkedDataLoader.COMPACTING_CONTEXT_OH
         )
-        const spec: object = compacted["@graph"]
+        const spec:({
+            "@type":"http://schema.org/OpeningHoursSpecification",
+            "dayOfWeek": string[]
+        })[] = compacted["@graph"]
         if (!spec) {
             return undefined
         }
@@ -173,17 +176,21 @@ export default class LinkedDataLoader {
                 }
                 return dow.toLowerCase().substring(0, 2)
             })
-            const opens: string = rule.opens
-            const closes: string = rule.closes === "23:59" ? "24:00" : rule.closes
-            allRules.push(...OH.ParseRule(dow + " " + opens + "-" + closes))
+            const opens: string = rule["http://schema.org/opens"] ?? rule["opens"]
+            let closes: string = (rule["http://schema.org/closes"] ?? rule["closes"])
+            closes = closes === "23:59" ? "24:00" : closes
+
+            allRules.push(...OH.parseRule(dow + " " + opens + "-" + closes))
         }
 
-        return OH.ToString(OH.MergeTimes(allRules))
+        return OH.toString(OH.MergeTimes(allRules))
     }
 
-    static async compact(data: object, options?: JsonLdLoaderOptions): Promise<object> {
+    static async compact(data: object, options?: JsonLdLoaderOptions): Promise<Record<string, string> | Record<string, string>[]> {
         if (Array.isArray(data)) {
-            return await Promise.all(data.map((point) => LinkedDataLoader.compact(point, options)))
+
+            const result: Awaited<Record<string, string> | Record<string, string>[]>[] = await Promise.all(data.map((point) => LinkedDataLoader.compact(point, options)))
+            return result.flatMap(x => Array.isArray(x) ? x : [x])
         }
 
         const country = options?.country
@@ -276,8 +283,8 @@ export default class LinkedDataLoader {
                 continue
             }
             if (k === "opening_hours") {
-                const oh = [].concat(...v.split(";").map((r) => OH.ParseRule(r) ?? []))
-                const merged = OH.ToString(OH.MergeTimes(oh ?? []))
+                const oh = [].concat(...v.split(";").map((r) => OH.parseRule(r) ?? []))
+                const merged = OH.toString(OH.MergeTimes(oh ?? []))
                 if (merged === d[k]) {
                     delete d[k]
                     continue
diff --git a/src/Logic/Web/VeloparkLoader.ts b/src/Logic/Web/VeloparkLoader.ts
index 09a33f967..e65b62cf2 100644
--- a/src/Logic/Web/VeloparkLoader.ts
+++ b/src/Logic/Web/VeloparkLoader.ts
@@ -97,9 +97,9 @@ export default class VeloparkLoader {
                             const startHour = spec.opens
                             const endHour = spec.closes === "23:59" ? "24:00" : spec.closes
                             const merged = OH.MergeTimes(
-                                OH.ParseRule(dayOfWeek + " " + startHour + "-" + endHour)
+                                OH.parseRule(dayOfWeek + " " + startHour + "-" + endHour)
                             )
-                            return OH.ToString(merged)
+                            return OH.toString(merged)
                         })
                         .join("; ")
                 )
diff --git a/src/UI/InputElement/Helpers/OpeningHours/OHTable.svelte b/src/UI/InputElement/Helpers/OpeningHours/OHTable.svelte
index 92ee16bc4..4b233ee18 100644
--- a/src/UI/InputElement/Helpers/OpeningHours/OHTable.svelte
+++ b/src/UI/InputElement/Helpers/OpeningHours/OHTable.svelte
@@ -110,7 +110,7 @@
     }
     let startMinutes = Math.round((start * 60) % 60)
     let endMinutes = Math.round((end * 60) % 60)
-    let newOhs = [...value.data]
+    let newOhs = [...(value.data ?? [])]
     for (
       let wd = Math.min(selectionStart[0], weekday);
       wd <= Math.max(selectionStart[0], weekday);
@@ -212,7 +212,7 @@
     {#each range(7) as wd}
       <td style="width: 13%; position: relative;">
         <div class="pointer-events-none h-0" style="z-index: 10">
-          {#each $value
+          {#each ($value ?? [])
             .filter((oh) => oh.weekday === wd)
             .map((oh) => OpeningHours.rangeAs24Hr(oh)) as range}
             <div
@@ -228,8 +228,8 @@
                 <button
                   class="pointer-events-auto w-fit self-center rounded-full p-1"
                   on:click={() => {
-                    const cleaned = value.data.filter((v) => !OpeningHours.isSame(v, range))
-                    console.log("Cleaned", cleaned, OpeningHours.ToString(value.data))
+                    const cleaned = (value.data??[]).filter((v) => !OpeningHours.isSame(v, range))
+                    console.log("Cleaned", cleaned, OpeningHours.toString(value.data ?? []))
                     value.set(cleaned)
                   }}
                 >
diff --git a/src/UI/OpeningHours/OpeningHours.ts b/src/UI/OpeningHours/OpeningHours.ts
index 2bf8df6bd..0d7d08920 100644
--- a/src/UI/OpeningHours/OpeningHours.ts
+++ b/src/UI/OpeningHours/OpeningHours.ts
@@ -46,31 +46,31 @@ export class OH {
     /**
      * const rules = [{weekday: 6,endHour: 17,endMinutes: 0,startHour: 13,startMinutes: 0},
      *                {weekday: 1,endHour: 12,endMinutes: 0,startHour: 10,startMinutes: 0}]
-     * OH.ToString(rules) // =>  "Tu 10:00-12:00; Su 13:00-17:00"
+     * OH.toString(rules) // =>  "Tu 10:00-12:00; Su 13:00-17:00"
      *
      * const rules = [{weekday: 3,endHour: 17,endMinutes: 0,startHour: 13,startMinutes: 0}, {weekday: 1,endHour: 12,endMinutes: 0,startHour: 10,startMinutes: 0}]
-     * OH.ToString(rules) // => "Tu 10:00-12:00; Th 13:00-17:00"
+     * OH.toString(rules) // => "Tu 10:00-12:00; Th 13:00-17:00"
      *
      * const rules = [ { weekday: 1, endHour: 17, endMinutes: 0, startHour: 13, startMinutes: 0 }, { weekday: 1, endHour: 12, endMinutes: 0, startHour: 10, startMinutes: 0 }]);
-     * OH.ToString(rules) // => "Tu 10:00-12:00, 13:00-17:00"
+     * OH.toString(rules) // => "Tu 10:00-12:00, 13:00-17:00"
      *
      * const rules = [ { weekday: 0, endHour: 12, endMinutes: 0, startHour: 10, startMinutes: 0 }, { weekday: 0, endHour: 17, endMinutes: 0, startHour: 13, startMinutes: 0}, { weekday: 1, endHour: 17, endMinutes: 0, startHour: 13, startMinutes: 0 }, { weekday: 1, endHour: 12, endMinutes: 0, startHour: 10, startMinutes: 0 }];
-     * OH.ToString(rules) // => "Mo-Tu 10:00-12:00, 13:00-17:00"
+     * OH.toString(rules) // => "Mo-Tu 10:00-12:00, 13:00-17:00"
      *
      * // should merge overlapping opening hours
      * const timerange0 = {weekday: 1, endHour: 23, endMinutes: 30, startHour: 23, startMinutes: 0 }
      * const touchingTimeRange = {  weekday: 1, endHour: 0, endMinutes: 0, startHour: 23, startMinutes: 30 }
-     * OH.ToString(OH.MergeTimes([timerange0, touchingTimeRange])) // => "Tu 23:00-00:00"
+     * OH.toString(OH.MergeTimes([timerange0, touchingTimeRange])) // => "Tu 23:00-00:00"
      *
      * // should merge touching opening hours
      * const timerange0 = {weekday: 1, endHour: 23, endMinutes: 30, startHour: 23, startMinutes: 0 }
      * const overlappingTimeRange =  { weekday: 1, endHour: 24, endMinutes: 0, startHour: 23, startMinutes: 30 }
-     * OH.ToString(OH.MergeTimes([timerange0, overlappingTimeRange])) // => "Tu 23:00-00:00"
+     * OH.toString(OH.MergeTimes([timerange0, overlappingTimeRange])) // => "Tu 23:00-00:00"
      *
      */
 
-    public static ToString(ohs: OpeningHour[]) {
-        if (ohs.length == 0) {
+    public static toString(ohs: OpeningHour[]): string {
+        if (!ohs || ohs.length == 0) {
             return ""
         }
         const partsPerWeekday: string[][] = [[], [], [], [], [], [], []]
@@ -284,35 +284,36 @@ export class OH {
     }
 
     /**
-     * Converts an OH-syntax rule into an object
+     * Converts a single OH-syntax rule into one or more objects.
+     * If the rule cannot be parsed, returns 'null'
      *
-     *
-     * const rules = OH.ParsePHRule("PH 12:00-17:00")
+     * const rules = OH.parsePHRule("PH 12:00-17:00")
      * rules.mode // => " "
      * rules.start // => "12:00"
      * rules.end // => "17:00"
      *
-     * OH.ParseRule("PH 12:00-17:00") // => null
-     * OH.ParseRule("Th[-1] off") // => null
+     * OH.parseRule("PH 12:00-17:00") // => null
+     * OH.parseRule("Th[-1] off") // => null
+     * OH.parseRule("Jul-Oct Mo-fr 11:00-19:00") // => null
      *
-     * const rules = OH.Parse("24/7");
+     * const rules = OH.parse("24/7");
      * rules.length // => 7
      * rules[0].startHour // => 0
-     * OH.ToString(rules) // => "24/7"
+     * OH.toString(rules) // => "24/7"
      *
-     * const rules = OH.ParseRule("11:00-19:00");
+     * const rules = OH.parseRule("11:00-19:00");
      * rules.length // => 7
      * rules[0].weekday // => 0
      * rules[0].startHour // => 11
      * rules[3].endHour // => 19
      *
-     * const rules = OH.ParseRule("Mo-Th 11:00-19:00");
+     * const rules = OH.parseRule("Mo-Th 11:00-19:00");
      * rules.length // => 4
      * rules[0].weekday // => 0
      * rules[0].startHour // => 11
      * rules[3].endHour // => 19
      *
-     * const rules = OH.ParseRule("Mo 20:00-02:00");
+     * const rules = OH.parseRule("Mo 20:00-02:00");
      * rules.length // => 2
      * rules[0].weekday // => 0
      * rules[0].startHour // => 20
@@ -321,13 +322,13 @@ export class OH {
      * rules[1].startHour // => 0
      * rules[1].endHour // => 2
      *
-     * const rules = OH.ParseRule("Mo 00:00-24:00")
+     * const rules = OH.parseRule("Mo 00:00-24:00")
      * rules.length // => 1
      * rules[0].weekday // => 0
      * rules[0].startHour // => 0
      * rules[0].endHour // => 24
      */
-    public static ParseRule(rule: string): OpeningHour[] {
+    public static parseRule(rule: string): OpeningHour[] {
         try {
             if (rule.trim() == "24/7") {
                 return OH.multiply(
@@ -346,33 +347,34 @@ export class OH {
             const split = rule.trim().replace(/, */g, ",").split(" ")
             if (split.length == 1) {
                 // First, try to parse this rule as a rule without weekdays
-                const timeranges = OH.ParseHhmmRanges(rule)
+                const timeranges = OH.parseHhmmRanges(rule)
                 const weekdays = [0, 1, 2, 3, 4, 5, 6]
                 return OH.multiply(weekdays, timeranges)
             }
 
             if (split.length == 2) {
-                const weekdays = OH.ParseWeekdayRanges(split[0])
-                const timeranges = OH.ParseHhmmRanges(split[1])
+                const weekdays = OH.parseWeekdayRanges(split[0])
+                const timeranges = OH.parseHhmmRanges(split[1])
                 return OH.multiply(weekdays, timeranges)
             }
-            return []
+            // THis rule is too complicated to parse
+            return null
         } catch (e) {
             console.log("Could not parse weekday rule ", rule)
-            return []
+            return null
         }
     }
 
     /**
      *
-     * OH.ParsePHRule("PH Off") // => {mode: "off"}
-     * OH.ParsePHRule("PH OPEN") // => {mode: "open"}
-     * OH.ParsePHRule("PH 10:00-12:00") // => {mode: " ", start: "10:00", end: "12:00"}
-     * OH.ParsePHRule(undefined) // => null
-     * OH.ParsePHRule(null) // => null
-     * OH.ParsePHRule("some random string") // => null
+     * OH.parsePHRule("PH Off") // => {mode: "off"}
+     * OH.parsePHRule("PH OPEN") // => {mode: "open"}
+     * OH.parsePHRule("PH 10:00-12:00") // => {mode: " ", start: "10:00", end: "12:00"}
+     * OH.parsePHRule(undefined) // => null
+     * OH.parsePHRule(null) // => null
+     * OH.parsePHRule("some random string") // => null
      */
-    public static ParsePHRule(str: string): {
+    public static parsePHRule(str: string): {
         mode: string
         start?: string
         end?: string
@@ -418,13 +420,21 @@ export class OH {
     }
 
     public static simplify(str: string): string {
-        return OH.ToString(OH.MergeTimes(OH.Parse(str)))
+        const parsed = OH.parse(str)
+        if(parsed === null){
+            // Parsing failed, probably too complicated to handle
+            return str
+        }
+        return OH.toString(OH.MergeTimes(parsed))
     }
 
     /**
      * Parses a string into Opening Hours
+     * Returns 'null' if the rules are to complicated to parse
+     *
+     * OH.parse("Feb-Oct Mo-Fr 10:00-12:00") // => null
      */
-    public static Parse(rules: string): OpeningHour[] {
+    public static parse(rules: string):null | OpeningHour[] {
         if (rules === undefined || rules === "") {
             return []
         }
@@ -438,12 +448,15 @@ export class OH {
                 continue
             }
             try {
-                const parsed = OH.ParseRule(rule)
-                if (parsed !== null) {
-                    ohs.push(...parsed)
+                const parsed = OH.parseRule(rule)
+                if (parsed === null) {
+                   return null // Parsing failed
                 }
+                ohs.push(...parsed)
+
             } catch (e) {
                 console.error("Could not parse ", rule, ": ", e)
+                return null
             }
         }
 
@@ -837,11 +850,11 @@ changes // => [[36000,61200], ["10:00", "17:00"]]
     }
 
     /**
-     * OH.ParseHhmmRanges("20:00-22:15") // => [{startHour: 20, startMinutes: 0, endHour: 22, endMinutes: 15}]
-     * OH.ParseHhmmRanges("20:00-02:15") // => [{startHour: 20, startMinutes: 0, endHour: 2, endMinutes: 15}]
-     * OH.ParseHhmmRanges("00:00-24:00") // => [{startHour: 0, startMinutes: 0, endHour: 24, endMinutes: 0}]
+     * OH.parseHhmmRanges("20:00-22:15") // => [{startHour: 20, startMinutes: 0, endHour: 22, endMinutes: 15}]
+     * OH.parseHhmmRanges("20:00-02:15") // => [{startHour: 20, startMinutes: 0, endHour: 2, endMinutes: 15}]
+     * OH.parseHhmmRanges("00:00-24:00") // => [{startHour: 0, startMinutes: 0, endHour: 24, endMinutes: 0}]
      */
-    private static ParseHhmmRanges(hhmms: string): {
+    private static parseHhmmRanges(hhmms: string): {
         startHour: number
         startMinutes: number
         endHour: number
@@ -858,21 +871,21 @@ changes // => [[36000,61200], ["10:00", "17:00"]]
             .filter((v) => v != null)
     }
 
-    private static ParseWeekday(weekday: string): number {
+    private static parseWeekday(weekday: string): number {
         return OH.daysIndexed[weekday.trim().toLowerCase()]
     }
 
-    private static ParseWeekdayRange(weekdays: string): number[] {
+    private static parseWeekdayRange(weekdays: string): number[] {
         const split = weekdays.split("-")
         if (split.length == 1) {
-            const parsed = OH.ParseWeekday(weekdays)
+            const parsed = OH.parseWeekday(weekdays)
             if (parsed == null) {
                 return null
             }
             return [parsed]
         } else if (split.length == 2) {
-            const start = OH.ParseWeekday(split[0])
-            const end = OH.ParseWeekday(split[1])
+            const start = OH.parseWeekday(split[0])
+            const end = OH.parseWeekday(split[1])
             if ((start ?? null) === null || (end ?? null) === null) {
                 return null
             }
@@ -886,11 +899,11 @@ changes // => [[36000,61200], ["10:00", "17:00"]]
         }
     }
 
-    private static ParseWeekdayRanges(weekdays: string): number[] {
+    private static parseWeekdayRanges(weekdays: string): number[] {
         const ranges = []
         const split = weekdays.split(",")
         for (const weekday of split) {
-            const parsed = OH.ParseWeekdayRange(weekday)
+            const parsed = OH.parseWeekdayRange(weekday)
             if (parsed === undefined || parsed === null) {
                 return null
             }
diff --git a/src/UI/OpeningHours/OpeningHoursState.ts b/src/UI/OpeningHours/OpeningHoursState.ts
index 2920086c3..a5f7ecb2c 100644
--- a/src/UI/OpeningHours/OpeningHoursState.ts
+++ b/src/UI/OpeningHours/OpeningHoursState.ts
@@ -55,10 +55,10 @@ export default class OpeningHoursState {
             const leftOvers: string[] = []
             const rules = str.split(";")
             for (const rule of rules) {
-                if (OH.ParseRule(rule) !== null) {
+                if (OH.parseRule(rule) !== null) {
                     continue
                 }
-                if (OH.ParsePHRule(rule) !== null) {
+                if (OH.parsePHRule(rule) !== null) {
                     continue
                 }
                 if (leftOvers.indexOf(rule) >= 0) {
@@ -72,7 +72,7 @@ export default class OpeningHoursState {
         let ph = ""
         const rules = valueWithoutPrefix.data?.split(";") ?? []
         for (const rule of rules) {
-            if (OH.ParsePHRule(rule) !== null) {
+            if (OH.parsePHRule(rule) !== null) {
                 // We found the rule containing the public holiday information
                 ph = rule
                 break
@@ -82,14 +82,12 @@ export default class OpeningHoursState {
 
         // Note: MUST be bound AFTER the leftover rules!
         this.normalOhs = valueWithoutPrefix.sync(
-            (str) => {
-                return OH.Parse(str)
-            },
+            (str) => OH.parse(str),
             [this.leftoverRules, this.phSelectorValue],
             (rules, oldString) => {
                 // We always add a ';', to easily add new rules. We remove the ';' again at the end of the function
                 // Important: spaces are _not_ allowed after a ';' as it'll destabilize the parsing!
-                let str = OH.ToString(rules) + ";"
+                let str = OH.toString(rules) + ";"
                 const ph = this.phSelectorValue.data
                 if (ph) {
                     str += " " + ph + ";" // There must be a space after every ";"
@@ -112,19 +110,5 @@ export default class OpeningHoursState {
                 return str
             }
         )
-        /*
-                const leftoverWarning = new VariableUiElement(
-                    leftoverRules.map((leftovers: string[]) => {
-                        if (leftovers.length == 0) {
-                            return ""
-                        }
-                        return new Combine([
-                            Translations.t.general.opening_hours.not_all_rules_parsed,
-                            new FixedUiElement(leftovers.map((r) => `${r}<br/>`).join("")).SetClass(
-                                "subtle"
-                            ),
-                        ])
-                    })
-                )*/
     }
 }
diff --git a/src/UI/OpeningHours/PublicHolidaySelector.svelte b/src/UI/OpeningHours/PublicHolidaySelector.svelte
index 7b2b4730a..410f36ed2 100644
--- a/src/UI/OpeningHours/PublicHolidaySelector.svelte
+++ b/src/UI/OpeningHours/PublicHolidaySelector.svelte
@@ -16,7 +16,7 @@
 
   onDestroy(
     value
-      .map((ph) => OH.ParsePHRule(ph), onDestroy)
+      .map((ph) => OH.parsePHRule(ph), onDestroy)
       .addCallbackAndRunD((parsed) => {
         if (parsed === null) {
           return
diff --git a/test/Logic/Web/LinkedDataLoader.spec.ts b/test/Logic/Web/LinkedDataLoader.spec.ts
index d442efb24..d3397a37c 100644
--- a/test/Logic/Web/LinkedDataLoader.spec.ts
+++ b/test/Logic/Web/LinkedDataLoader.spec.ts
@@ -73,5 +73,6 @@ describe("LinkedDataLoader", () => {
         }
         const compacted = await LinkedDataLoader.compact(graph)
         expect(compacted.phone).equal("+32 89 41 35 20")
+        expect(compacted.opening_hours).equal("Mo 12:00-18:30; Tu-Sa 08:00-18:30; Su 08:00-12:00")
     })
 })