Created a period table for date ranges and made the recipes dependent on it instead of having arbitrary date ranges. This will enable easy copying into new months.

overlord/src/app/recipe/recipe.service.ts

@@ -1,6 +1,6 @@
 import { HttpClient, HttpParams } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Observable } from 'rxjs/internal/Observable';
+import { Observable, of as observableOf } from 'rxjs';
 import { catchError } from 'rxjs/operators';
 
 import { ErrorLoggerService } from '../core/error-logger.service';
@@ -22,9 +22,12 @@ export class RecipeService {
       .pipe(catchError(this.log.handleError(serviceName, `get id=${id}`))) as Observable<Recipe>;
   }
 
-  list(): Observable<Recipe[]> {
+  list(periodId: string | null): Observable<Recipe[]> {
+    if (periodId === null) {
+      return observableOf([]);
+    }
     return this.http
-      .get<Recipe[]>(`${url}/list`)
+      .get<Recipe[]>(`${url}/list`, { params: new HttpParams().set('p', periodId) })
       .pipe(catchError(this.log.handleError(serviceName, 'getList'))) as Observable<Recipe[]>;
   }