use current month for last_updated value

main.py

@@ -1,5 +1,6 @@
 import re
-import time
+from calendar import timegm
+from datetime import date
 
 from fastapi import Depends, FastAPI, Response
 from fastapi.staticfiles import StaticFiles
@@ -46,7 +47,7 @@ async def list_items(db: Session = Depends(get_db)):
 @app.put("/api/items/{id}")
 async def put_item(id: str, item: Item, db: Session = Depends(get_db)):
     if item.last_updated is None:
-        item.last_updated = rough_timestamp()
+        item.last_updated = month_timestamp()
     if crud.put_item(db, id, item) == crud.PutItemResult.UPDATED:
         return Response(b"", status_code=204)
     return Response(b"", status_code=201)
@@ -57,10 +58,9 @@ async def delete_item(id: str, db: Session = Depends(get_db)):
     crud.delete_item(db, id)
 
 
-def rough_timestamp() -> int:
-    """Provides an current timestamp with reduced resolution, to improve anonymity."""
-    granularity = 2**20  # about 12 days
-    return int(time.time()) // granularity * granularity
+def month_timestamp() -> int:
+    """Provides the timestamp of the current month's beginning (for improved privacy)"""
+    return timegm(date.today().replace(day=1).timetuple())
 
 
 app.mount("/", StaticFiles(directory="static", html=True), name="static")

static/form.js

@@ -176,5 +176,6 @@ function formCoordsToMap() {
 
 function formatTimestamp(ts) {
     const date = new Date(ts * 1000);
-    return date.toLocaleDateString();
+    // using Swedish format as a hack to get an iso formatted date
+    return date.toLocaleDateString("sv", {timeZone: "UTC"}).replace(/\-\d+$/,'') 
 }