This might be a better solution - fix QUnitType and add ManipulateQType

Author: bensaufley

types/index.d.ts

@@ -27,9 +27,14 @@ declare namespace dayjs {
 
   export type UnitType = UnitTypeLong | UnitTypeLongPlural | UnitTypeShort;
 
+  type WithQuarters<T>  = T & 'quarter' | 'quarters' | 'Q';
+  
   export type OpUnitType = UnitType | "week" | "weeks" | 'w';
-  export type QUnitType = UnitType | "quarter" | "quarters" | 'Q';
+  export type QUnitType = WithQuarters<OpUnitType>;
+  
   export type ManipulateType = Exclude<OpUnitType, 'date' | 'dates'>;
+  export type ManipulateQType = WithQuarters<ManipulateType>;
+  
   class Dayjs {
     constructor (config?: ConfigType)
     /**

types/plugin/quarterOfYear.d.ts

@@ -1,10 +1,4 @@
-import {
-  PluginFunc,
-  ConfigType,
-  ManipulateType,
-  QUnitType,
-  OpUnitType
-} from 'dayjs'
+import { PluginFunc, ConfigType, ManipulateQType, QUnitType } from 'dayjs'
 
 declare const plugin: PluginFunc
 export = plugin
@@ -15,18 +9,18 @@ declare module 'dayjs' {
 
     quarter(quarter: number): Dayjs
 
-    add(value: number, unit: QUnitType | ManipulateType): Dayjs
+    add(value: number, unit: ManipulateQType): Dayjs
 
-    subtract(value: number, unit: QUnitType | ManipulateType): Dayjs
+    subtract(value: number, unit: ManipulateQType): Dayjs
 
-    startOf(unit: QUnitType | OpUnitType): Dayjs
+    startOf(unit: QUnitType): Dayjs
 
-    endOf(unit: QUnitType | OpUnitType): Dayjs
+    endOf(unit: QUnitType): Dayjs
 
-    isSame(date?: ConfigType, unit?: QUnitType | OpUnitType): boolean
+    isSame(date?: ConfigType, unit?: QUnitType): boolean
 
-    isBefore(date?: ConfigType, unit?: QUnitType | OpUnitType): boolean
+    isBefore(date?: ConfigType, unit?: QUnitType): boolean
 
-    isAfter(date?: ConfigType, unit?: QUnitType | OpUnitType): boolean
+    isAfter(date?: ConfigType, unit?: QUnitType): boolean
   }
 }