Fix timezone to Sydney

app/routes/api.py

@@ -1,6 +1,8 @@
 from flask import Blueprint, jsonify
+from app import SYDNEY_TZ
 from app.auth import login_required
 from app.db import query
+from datetime import timezone
 
 bp = Blueprint("api", __name__, url_prefix="/api")
 
@@ -16,7 +18,7 @@ def chart_data(user_id):
         (user_id,),
     )
 
-    labels = [c["checked_in_at"].strftime("%d %b") for c in checkins]
+    labels = [c["checked_in_at"].replace(tzinfo=timezone.utc).astimezone(SYDNEY_TZ).strftime("%d %b") for c in checkins]
     weights = [float(c["weight_kg"]) for c in checkins]
     bmis = [float(c["bmi"]) if c["bmi"] else None for c in checkins]
 
@@ -88,7 +90,7 @@ def weekly_change(user_id):
         prev_w = float(checkins[i - 1]["weight_kg"])
         curr_w = float(checkins[i]["weight_kg"])
         change = round(curr_w - prev_w, 1)
-        label = checkins[i]["checked_in_at"].strftime("%d %b")
+        label = checkins[i]["checked_in_at"].replace(tzinfo=timezone.utc).astimezone(SYDNEY_TZ).strftime("%d %b")
         labels.append(label)
         changes.append(change)