diff --git a/src/api/splatnet2-types.ts b/src/api/splatnet2-types.ts
index 056b54d..1c3f936 100644
--- a/src/api/splatnet2-types.ts
+++ b/src/api/splatnet2-types.ts
@@ -101,7 +101,7 @@ interface SpecialWeapon {
 }
 
 interface Player {
-    clothes: Gear & {kind: 'clothes'};
+    clothes: Gear & {kind: GearType.CLOTHES};
     star_rank: number;
     head_skills: Skills;
     nickname: string;
@@ -109,13 +109,13 @@ interface Player {
     weapon: Weapon;
     player_rank: number;
     max_league_point_team: number;
-    shoes: Gear & {kind: 'shoes'};
+    shoes: Gear & {kind: GearType.SHOES};
     clothes_skills: Skills;
     udemae_tower: Rank;
     udemae_clam: Rank;
     udemae_rainmaker: Rank;
     player_type: PlayerType;
-    head: Gear & {kind: 'head'};
+    head: Gear & {kind: GearType.HEAD};
     max_league_point_pair: number;
     principal_id: string;
     udemae_zones: Rank;
@@ -127,9 +127,14 @@ interface Gear {
     id: string;
     rarity: number;
     image: string;
-    kind: 'clothes' | 'shoes' | 'head';
+    kind: GearType;
     thumbnail: string;
 }
+export enum GearType {
+    CLOTHES = 'clothes',
+    SHOES = 'shoes',
+    HEAD = 'head',
+}
 interface Brand {
     image: string;
     frequent_skill?: Skill;
@@ -232,38 +237,6 @@ export interface Timeline {
     };
 }
 
-interface ShopMerchandise {
-    skill: Skill;
-    end_time: number;
-    gear: Gear;
-    id: string;
-    price: number;
-    kind: string;
-}
-
-interface CoopSchedule {
-    weapons: CoopWeapon[];
-    stage: {
-        image: string;
-        name: string;
-    };
-    start_time: number;
-    end_time: number;
-}
-
-type CoopWeapon = CoopStandardWeapon | CoopSpecialWeapon;
-interface CoopStandardWeapon {
-    weapon: Omit<Weapon, 'sub' | 'special'>;
-    id: string;
-}
-interface CoopSpecialWeapon {
-    id: string;
-    coop_special_weapon: {
-        image: string;
-        name: string;
-    };
-}
-
 interface CoopRewardGear {
     available_time: number;
     gear: Gear;
@@ -300,17 +273,19 @@ interface ScheduleItem {
 /** GET /records/hero */
 export interface HeroRecords {
     stage_infos: StageInfo[];
-    summary: {
-        weapon_cleared_info: Record<string, boolean>;
-        honor: {
-            code: string;
-            name: string;
-        };
-        clear_rate: number;
-    };
+    summary: HeroRecordsSummary;
     weapon_map: Record<string, HeroWeapon>;
 }
 
+interface HeroRecordsSummary {
+    weapon_cleared_info: Record<string, boolean>;
+    honor: HeroHonor;
+    clear_rate: number;
+}
+interface HeroHonor {
+    code: string;
+    name: string;
+}
 interface StageInfo {
     clear_weapons: Record<string, StageCleared>;
     stage: HeroStage;
@@ -338,17 +313,23 @@ export interface XPowerRankingSummary {
     splat_zones: XPowerRankingRecords;
 }
 
-interface XPowerRankingRecords {
+/** GET /x_power_ranking/{season}/{rule} */
+export interface XPowerRankingRecords {
     weapon_ranking: null;
     season_id: string;
     top_rankings_count: number;
     top_rankings: XPowerRankingRecordsRanking[];
-    status: string;
+    status: XPowerRankingStatus;
     rule: Rule;
     start_time: number;
     end_time: number;
     my_ranking: null;
 }
+
+export enum XPowerRankingStatus {
+    CALCULATED = 'calculated',
+    ONGOING = 'ongoing',
+}
 interface XPowerRankingRecordsRanking {
     name: string;
     principal_id: string;
@@ -367,34 +348,35 @@ export interface PastFestivals {
 }
 
 interface Festival {
-    colors: {
-        middle: InkColour;
-        bravo: InkColour;
-        alpha: InkColour;
-    };
+    colors: FestivalInkColours;
     festival_id: number;
-    names: {
-        bravo_short: string;
-        bravo_long: string;
-        alpha_short: string;
-        alpha_long: string;
-    };
-    images: {
-        bravo: string;
-        alpha: string;
-        panel: string;
-    };
-    times: {
-        start: number;
-        announce: number;
-        end: number;
-        result: number;
-    };
-    special_stage: {
-        name: string;
-        id: string;
-        image: string;
-    };
+    names: FestivalTeamNames;
+    images: FestivalImages;
+    times: FestivalTimes;
+    special_stage: Stage;
+}
+
+interface FestivalTeamNames {
+    bravo_short: string;
+    bravo_long: string;
+    alpha_short: string;
+    alpha_long: string;
+}
+interface FestivalImages {
+    bravo: string;
+    alpha: string;
+    panel: string;
+}
+interface FestivalTimes {
+    start: number;
+    announce: number;
+    end: number;
+    result: number;
+}
+interface FestivalInkColours {
+    middle: InkColour;
+    bravo: InkColour;
+    alpha: InkColour;
 }
 
 interface InkColour {
@@ -450,18 +432,20 @@ interface FestivalResults1 {
 /** GET /league_match_ranking/{league}/{region} */
 export interface LeagueMatchRankings {
     start_time: number;
-    league_type: {
-        name: string;
-        key: string;
-    };
-    league_ranking_region: {
-        code: string;
-        id: number;
-    };
+    league_type: LeagueType;
+    league_ranking_region: LeagueRankingRegion;
     rankings: LeagueMatchRanking[];
     league_id: string;
 }
 
+interface LeagueType {
+    key: string; // "team", "pair"
+    name: string; // "Mode: Team", "Mode: Pair"
+}
+interface LeagueRankingRegion {
+    id: number; // 0, 1, 2, 4
+    code: string; // ALL, JP, US, EU
+}
 interface LeagueMatchRanking {
     tag_members: LeagueTagMember[];
     point: number;
@@ -479,16 +463,18 @@ interface LeagueTagMember {
 export interface Results {
     results: MatchResults[];
     unique_id: string;
-    summary: {
-        kill_count_average: number;
-        victory_count: number;
-        count: number;
-        defeat_count: number;
-        special_count_average: number;
-        victory_rate: number;
-        death_count_average: number;
-        assist_count_average: number;
-    };
+    summary: ResultsSummary;
+}
+
+interface ResultsSummary {
+    kill_count_average: number;
+    victory_count: number;
+    count: number;
+    defeat_count: number;
+    special_count_average: number;
+    victory_rate: number;
+    death_count_average: number;
+    assist_count_average: number;
 }
 
 type MatchResults = RegularMatchResults | RankedMatchResults;
@@ -669,6 +655,18 @@ interface CoopWaveWaterLevel {
     key: string;
     name: string;
 }
+type CoopWeapon = CoopStandardWeapon | CoopSpecialWeapon;
+interface CoopStandardWeapon {
+    weapon: Omit<Weapon, 'sub' | 'special'>;
+    id: string;
+}
+interface CoopSpecialWeapon {
+    id: string;
+    coop_special_weapon: {
+        image: string;
+        name: string;
+    };
+}
 
 interface CoopSummaryResult {
     schedule: CoopSchedule;
@@ -710,6 +708,15 @@ export interface CoopSchedules {
     schedules: CoopScheduleTimes[];
 }
 
+interface CoopSchedule {
+    weapons: CoopWeapon[];
+    stage: {
+        image: string;
+        name: string;
+    };
+    start_time: number;
+    end_time: number;
+}
 interface CoopScheduleTimes {
     start_time: number;
     end_time: number;
@@ -721,6 +728,15 @@ export interface ShopMerchandises {
     ordered_info: null;
 }
 
+interface ShopMerchandise {
+    skill: Skill;
+    end_time: number;
+    gear: Gear;
+    id: string;
+    price: number;
+    kind: GearType;
+}
+
 /** POST /share/profile, POST /share/results/summary, POST /share/results/1 */
 export interface ShareResponse {
     url: string;
diff --git a/src/api/splatnet2-xrank.ts b/src/api/splatnet2-xrank.ts
index 2df8b1b..4a931a9 100644
--- a/src/api/splatnet2-xrank.ts
+++ b/src/api/splatnet2-xrank.ts
@@ -51,8 +51,8 @@ export function getSeason(year: number | Date | string, month?: number): Season
     if (start.getUTCFullYear() < 2018 || (start.getUTCFullYear() === 2018 && start.getUTCMonth() < 3)) return null;
 
     const end = new Date(Date.UTC(
-        start.getFullYear() + (start.getMonth() === 11 ? 1 : 0),
-        start.getMonth() === 11 ? 0 : start.getMonth() + 1,
+        start.getUTCFullYear() + (start.getUTCMonth() === 11 ? 1 : 0),
+        start.getUTCMonth() === 11 ? 0 : start.getUTCMonth() + 1,
     ));
 
     const id = toSeasonId(start.getUTCFullYear(), start.getUTCMonth() + 1);
@@ -88,15 +88,15 @@ export function getNextSeason(season: Season | number, month?: number): Season |
     }
 
     const start = new Date(Date.UTC(
-        current_start.getFullYear() + (current_start.getMonth() === 11 ? 1 : 0),
-        current_start.getMonth() === 11 ? 0 : current_start.getMonth() + 1,
+        current_start.getUTCFullYear() + (current_start.getUTCMonth() === 11 ? 1 : 0),
+        current_start.getUTCMonth() === 11 ? 0 : current_start.getUTCMonth() + 1,
     ));
 
     if (Date.now() < start.getTime()) return null;
 
     const end = new Date(Date.UTC(
-        start.getFullYear() + (start.getMonth() === 11 ? 1 : 0),
-        start.getMonth() === 11 ? 0 : start.getMonth() + 1,
+        start.getUTCFullYear() + (start.getUTCMonth() === 11 ? 1 : 0),
+        start.getUTCMonth() === 11 ? 0 : start.getUTCMonth() + 1,
     ));
 
     const id = toSeasonId(start.getUTCFullYear(), start.getUTCMonth() + 1);
@@ -117,15 +117,15 @@ export function getPreviousSeason(season: Season | number, month?: number): Seas
     const current_start = typeof season === 'number' ? new Date(Date.UTC(season, month!)) : season.start;
 
     const start = new Date(Date.UTC(
-        current_start.getFullYear() - (current_start.getMonth() === 0 ? 1 : 0),
-        current_start.getMonth() === 0 ? 11 : current_start.getMonth() - 1,
+        current_start.getUTCFullYear() - (current_start.getUTCMonth() === 0 ? 1 : 0),
+        current_start.getUTCMonth() === 0 ? 11 : current_start.getUTCMonth() - 1,
     ));
 
     if (start.getUTCFullYear() < 2018 || (start.getUTCFullYear() === 2018 && start.getUTCMonth() < 3)) return null;
 
     const end = new Date(Date.UTC(
-        start.getFullYear() + (start.getMonth() === 11 ? 1 : 0),
-        start.getMonth() === 11 ? 0 : start.getMonth() + 1,
+        start.getUTCFullYear() + (start.getUTCMonth() === 11 ? 1 : 0),
+        start.getUTCMonth() === 11 ? 0 : start.getUTCMonth() + 1,
     ));
 
     const id = toSeasonId(start.getUTCFullYear(), start.getUTCMonth() + 1);
@@ -151,6 +151,13 @@ export function toSeasonId(year: number, month: number) {
     if (year < 2000) throw new Error('Invalid season ID');
     if (nextyear >= 2100) throw new Error('Invalid season ID');
 
+    if (year < 2018) throw new Error('Invalid season ID');
+    if (year === 2018 && month < 5) throw new Error('Invalid season ID');
+
+    const now = new Date();
+    if (year > now.getUTCFullYear()) throw new Error('Invalid season ID');
+    if (year === now.getUTCFullYear() && month > (now.getUTCMonth() + 1)) throw new Error('Invalid season ID');
+
     if (year === 2018 && month === 5) month = 4;
 
     return ('' + (year - 2000)).padStart(2, '0') +
diff --git a/src/api/splatnet2.ts b/src/api/splatnet2.ts
index 2b03a96..d8da0ed 100644
--- a/src/api/splatnet2.ts
+++ b/src/api/splatnet2.ts
@@ -5,9 +5,9 @@ import { WebServiceToken } from './coral-types.js';
 import { NintendoAccountUser } from './na.js';
 import { ErrorResponse } from './util.js';
 import CoralApi from './coral.js';
-import { ActiveFestivals, CoopResult, CoopResults, CoopSchedules, HeroRecords, NicknameAndIcons, PastFestivals, Records, Result, Results, Schedules, ShareResponse, ShopMerchandises, Stages, Timeline, WebServiceError, XPowerRankingSummary } from './splatnet2-types.js';
+import { ActiveFestivals, CoopResult, CoopResults, CoopSchedules, HeroRecords, LeagueMatchRankings, NicknameAndIcons, PastFestivals, Records, Result, Results, Schedules, ShareResponse, ShopMerchandises, Stages, Timeline, WebServiceError, XPowerRankingRecords, XPowerRankingSummary } from './splatnet2-types.js';
 import { timeoutSignal } from '../util/misc.js';
-import { toSeasonId, Rule as XPowerRankingRule } from './splatnet2-xrank.js';
+import { toSeasonId, Rule as XPowerRankingRule, Season } from './splatnet2-xrank.js';
 
 const debug = createDebug('nxapi:api:splatnet2');
 
@@ -93,7 +93,11 @@ export default class SplatNet2Api {
         return this.fetch<HeroRecords>('/records/hero');
     }
 
-    async getXPowerRankingSummary(season: string | Date) {
+    async getXPowerRankingSummary(season: string | Date | Season) {
+        if (typeof season === 'object' && 'start' in season) {
+            season = season.id;
+        }
+
         if (season instanceof Date) {
             season = toSeasonId(season.getUTCFullYear(), season.getUTCMonth() + 1);
         }
@@ -110,7 +114,11 @@ export default class SplatNet2Api {
         return this.fetch<XPowerRankingSummary>('/x_power_ranking/' + season + '/summary');
     }
 
-    async getXPowerRankingLeaderboard(season: string | Date, rule: XPowerRankingRule, page: number = 1) {
+    async getXPowerRankingLeaderboard(season: string | Date | Season, rule: XPowerRankingRule, page: number = 1) {
+        if (typeof season === 'object' && 'start' in season) {
+            season = season.id;
+        }
+
         if (season instanceof Date) {
             season = toSeasonId(season.getUTCFullYear(), season.getUTCMonth() + 1);
         }
@@ -124,19 +132,27 @@ export default class SplatNet2Api {
             throw new Error('Invalid season ID');
         }
 
-        return this.fetch<unknown>('/x_power_ranking/' + season + '/' + rule + '?page=' + page);
+        return this.fetch<XPowerRankingRecords>('/x_power_ranking/' + season + '/' + rule + '?page=' + page);
     }
 
     async getPastFestivals() {
         return this.fetch<PastFestivals>('/festivals/pasts');
     }
 
-    async getLeagueMatchRanking(id: string, region: LeagueRegion) {
+    async getLeagueMatchRanking(id: string, region: LeagueRegion): Promise<LeagueMatchRankings>
+    async getLeagueMatchRanking(date: Date, type: LeagueType, region: LeagueRegion): Promise<LeagueMatchRankings>
+    async getLeagueMatchRanking(id: string | Date, arg1: LeagueRegion | LeagueType, arg2?: LeagueRegion) {
+        const region = id instanceof Date ? arg2! : arg1 as LeagueRegion;
+
+        if (id instanceof Date) {
+            id = toLeagueId(id, arg1 as LeagueType);
+        }
+
         if (!id.match(LEAGUE_ID)) {
             throw new Error('Invalid league ID');
         }
 
-        return this.fetch<PastFestivals>('/league_match_ranking/' + id + '/' + region);
+        return this.fetch<LeagueMatchRankings>('/league_match_ranking/' + id + '/' + region);
     }
 
     async getResults() {