diff --git a/data/instance/volebnakalkulacka.sk/nrsr-2023/election.json b/data/instance/volebnakalkulacka.sk/nrsr-2023/election.json
index bbaa517ea..d18c553c7 100644
--- a/data/instance/volebnakalkulacka.sk/nrsr-2023/election.json
+++ b/data/instance/volebnakalkulacka.sk/nrsr-2023/election.json
@@ -8,15 +8,10 @@
     "id": "05c64bc5-aa2e-4457-ab30-336f7cf9131b",
     "key": "nrsr-2023"
   },
-  "rounds": [
+  "votingHours": [
     {
-      "number": 0,
-      "votingHours": [
-        {
-          "start": "2023-09-30T07:00:00+02:00",
-          "end": "2023-09-30T22:00:00+02:00"
-        }
-      ]
+      "start": "2023-09-30T07:00:00+02:00",
+      "end": "2023-09-30T22:00:00+02:00"
     }
   ]
 }
diff --git a/data/schemas/candidates-answers.schema.json b/data/schemas/candidates-answers.schema.json
index e3a917860..23296df59 100644
--- a/data/schemas/candidates-answers.schema.json
+++ b/data/schemas/candidates-answers.schema.json
@@ -9,5 +9,5 @@
       "$ref": "./answers.schema.json"
     }
   },
-  "additionalProperties": false
+  "unevaluatedProperties": false
 }
diff --git a/data/schemas/election.schema.json b/data/schemas/election.schema.json
index 742453d23..2c2d4ba34 100644
--- a/data/schemas/election.schema.json
+++ b/data/schemas/election.schema.json
@@ -118,8 +118,18 @@
       "items": {
         "$ref": "./round.schema.json"
       }
+    },
+    "votingHours": {
+      "title": "Voting hours",
+      "description": "One or multiple voting hours for the election",
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "$ref": "./time-period.schema.json"
+      }
     }
   },
+  "unevaluatedProperties": false,
   "required": [
     "id",
     "key",
@@ -127,5 +137,17 @@
     "title",
     "shortTitle",
     "calculatorGroup"
-  ]
+  ],
+  "dependentSchemas": {
+    "rounds": {
+      "not": {
+        "required": ["votingHours"]
+      }
+    },
+    "votingHours": {
+      "not": {
+        "required": ["rounds"]
+      }
+    }
+  }
 }
diff --git a/data/schemas/round.schema.json b/data/schemas/round.schema.json
index 09c36ee6b..6fac631d8 100644
--- a/data/schemas/round.schema.json
+++ b/data/schemas/round.schema.json
@@ -18,44 +18,7 @@
       "type": "array",
       "minItems": 1,
       "items": {
-        "title": "Voting period",
-        "type": "object",
-        "unevaluatedProperties": false,
-        "properties": {
-          "start": {
-            "title": "Start time",
-            "description": "Start date (or time) of a voting period in the ISO 8601 format",
-            "oneOf": [
-              {
-                "type": "string",
-                "format": "date",
-                "examples": ["2023-01-13"]
-              },
-              {
-                "type": "string",
-                "format": "date-time",
-                "examples": ["2023-01-13T14:00:00+01:00"]
-              }
-            ]
-          },
-          "end": {
-            "title": "End time",
-            "description": "End date (or time) of a voting period in the ISO 8601 format",
-            "oneOf": [
-              {
-                "type": "string",
-                "format": "date",
-                "examples": ["2023-01-13"]
-              },
-              {
-                "type": "string",
-                "format": "date-time",
-                "examples": ["2023-01-13T14:00:00+01:00"]
-              }
-            ]
-          }
-        },
-        "required": ["start", "end"]
+        "$ref": "./time-period.schema.json"
       }
     }
   },
diff --git a/data/schemas/time-period.schema.json b/data/schemas/time-period.schema.json
new file mode 100644
index 000000000..73d4b4190
--- /dev/null
+++ b/data/schemas/time-period.schema.json
@@ -0,0 +1,43 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://www.volebnikalkulacka.cz/data/schemas/time-period.schema.json",
+  "title": "Time period",
+  "description": "Time period from–to",
+  "type": "object",
+  "properties": {
+    "start": {
+      "title": "Start time",
+      "description": "Start date (or time) of a voting period in the ISO 8601 format",
+      "oneOf": [
+        {
+          "type": "string",
+          "format": "date",
+          "examples": ["2023-01-13"]
+        },
+        {
+          "type": "string",
+          "format": "date-time",
+          "examples": ["2023-01-13T14:00:00+01:00"]
+        }
+      ]
+    },
+    "end": {
+      "title": "End time",
+      "description": "End date (or time) of a voting period in the ISO 8601 format",
+      "oneOf": [
+        {
+          "type": "string",
+          "format": "date",
+          "examples": ["2023-01-13"]
+        },
+        {
+          "type": "string",
+          "format": "date-time",
+          "examples": ["2023-01-13T14:00:00+01:00"]
+        }
+      ]
+    }
+  },
+  "unevaluatedProperties": false,
+  "required": ["start", "end"]
+}
diff --git a/data/types/election.ts b/data/types/election.ts
index c951298b2..09d83f030 100644
--- a/data/types/election.ts
+++ b/data/types/election.ts
@@ -70,7 +70,7 @@ export type Number = number;
  *
  * @minItems 1
  */
-export type VotingHours = [VotingPeriod, ...VotingPeriod[]];
+export type VotingHours = [TimePeriod, ...TimePeriod[]];
 /**
  * Start date (or time) of a voting period in the ISO 8601 format
  */
@@ -79,6 +79,12 @@ export type StartTime = string | string;
  * End date (or time) of a voting period in the ISO 8601 format
  */
 export type EndTime = string | string;
+/**
+ * One or multiple voting hours for the election
+ *
+ * @minItems 1
+ */
+export type VotingHours1 = [TimePeriod, ...TimePeriod[]];
 
 /**
  * Election provides various details about an election such as districts and rounds
@@ -95,6 +101,7 @@ export interface Election {
   calculatorGroup: CalculatorGroup;
   districts?: OrderedListOfElectionDistricts;
   rounds?: OrderedListOfElectionRounds;
+  votingHours?: VotingHours1;
   [k: string]: unknown;
 }
 /**
@@ -121,7 +128,10 @@ export interface Round {
   votingHours?: VotingHours;
   [k: string]: unknown;
 }
-export interface VotingPeriod {
+/**
+ * Time period from–to
+ */
+export interface TimePeriod {
   start: StartTime;
   end: EndTime;
   [k: string]: unknown;
diff --git a/data/types/elections.ts b/data/types/elections.ts
index f40676a33..c943114f5 100644
--- a/data/types/elections.ts
+++ b/data/types/elections.ts
@@ -70,7 +70,7 @@ export type Number = number;
  *
  * @minItems 1
  */
-export type VotingHours = [VotingPeriod, ...VotingPeriod[]];
+export type VotingHours = [TimePeriod, ...TimePeriod[]];
 /**
  * Start date (or time) of a voting period in the ISO 8601 format
  */
@@ -79,6 +79,12 @@ export type StartTime = string | string;
  * End date (or time) of a voting period in the ISO 8601 format
  */
 export type EndTime = string | string;
+/**
+ * One or multiple voting hours for the election
+ *
+ * @minItems 1
+ */
+export type VotingHours1 = [TimePeriod, ...TimePeriod[]];
 /**
  * List of elections
  */
@@ -99,6 +105,7 @@ export interface Election {
   calculatorGroup: CalculatorGroup;
   districts?: OrderedListOfElectionDistricts;
   rounds?: OrderedListOfElectionRounds;
+  votingHours?: VotingHours1;
   [k: string]: unknown;
 }
 /**
@@ -125,7 +132,10 @@ export interface Round {
   votingHours?: VotingHours;
   [k: string]: unknown;
 }
-export interface VotingPeriod {
+/**
+ * Time period from–to
+ */
+export interface TimePeriod {
   start: StartTime;
   end: EndTime;
   [k: string]: unknown;
diff --git a/data/types/round.ts b/data/types/round.ts
index 6e09a8eb4..c39cee138 100644
--- a/data/types/round.ts
+++ b/data/types/round.ts
@@ -14,7 +14,7 @@ export type Number = number;
  *
  * @minItems 1
  */
-export type VotingHours = [VotingPeriod, ...VotingPeriod[]];
+export type VotingHours = [TimePeriod, ...TimePeriod[]];
 /**
  * Start date (or time) of a voting period in the ISO 8601 format
  */
@@ -32,7 +32,10 @@ export interface Round {
   votingHours?: VotingHours;
   [k: string]: unknown;
 }
-export interface VotingPeriod {
+/**
+ * Time period from–to
+ */
+export interface TimePeriod {
   start: StartTime;
   end: EndTime;
   [k: string]: unknown;
diff --git a/data/types/timePeriod.ts b/data/types/timePeriod.ts
new file mode 100644
index 000000000..4b1324aa7
--- /dev/null
+++ b/data/types/timePeriod.ts
@@ -0,0 +1,24 @@
+/* eslint-disable */
+/**
+ * This file was automatically generated by json-schema-to-typescript.
+ * DO NOT MODIFY IT BY HAND. Instead, modify the source JSONSchema file,
+ * and run json-schema-to-typescript to regenerate this file.
+ */
+
+/**
+ * Start date (or time) of a voting period in the ISO 8601 format
+ */
+export type StartTime = string;
+/**
+ * End date (or time) of a voting period in the ISO 8601 format
+ */
+export type EndTime = string;
+
+/**
+ * Time period from–to
+ */
+export interface TimePeriod {
+  start: StartTime;
+  end: EndTime;
+  [k: string]: unknown;
+}