Update app.py

app.py

@@ -1,16 +1,16 @@
 # app.py
 #
 # Hugging Face Space – Live U.S. Debt Clock
-# · Pulls the last 10 Treasury “Debt to the Penny” points
-# · Derives a $/sec rate from the two most-recent *different* days
-# · Computes the *current* debt by projecting from the timestamp
-#   of the latest record → now
-# · Refreshes every 5 min so the rate/value stay current
+# • Pulls the last 10 Treasury “Debt to the Penny” points
+# • Derives a $/sec rate from the last two *different* days
+# • Projects the current debt from the timestamp of the latest record
 #
 # Endpoints
 #   /            – simple text “running” check
 #   /api/debt    – JSON { startingDebt, ratePerSecond, asOf }
 #   /api/ping    – lightweight uptime probe
+#
+# ────────────────────────────────────────────────────────────
 
 import os, time, threading, requests
 from flask import Flask, jsonify
@@ -19,10 +19,10 @@ app = Flask(__name__)
 
 # ─────────────────── runtime state ────────────────────
 DEBT_STATE = {
-    "debt_at_record": 0.0,       # value at latest record date
-    "record_time":    0.0,       # epoch seconds for that record date (00:00 UTC)
-    "rate_per_sec":   0.0,       # $/s derived from last-two-points
-    "last_refresh":   0.0        # when we last hit the API
+    "debt_at_record": 0.0,   # value at latest record date
+    "record_time":    0.0,   # epoch seconds for that record date (00:00 UTC)
+    "rate_per_sec":   0.0,   # $/s derived from last-two-points
+    "last_refresh":   0.0
 }
 
 # ─────────────────── helpers ──────────────────────────
@@ -42,7 +42,7 @@ def load_debt_records():
     ]
 
 def epoch(date_str):
-    # record_date is YYYY-MM-DD (assume 00:00 UTC)
+    # record_date is YYYY-MM-DD (interpreted as 00:00 UTC)
     return time.mktime(time.strptime(date_str, "%Y-%m-%d"))
 
 # ─────────────────── background refresher ────────────
@@ -52,7 +52,7 @@ def refresher():
             recs = load_debt_records()             # newest first
             (d0_date, d0_val) = recs[0]
 
-            # find previous day with a *different* value
+            # find previous day with *different* value
             prev = next((d for d in recs[1:] if d[1] != d0_val), None)
             if prev is None:
                 raise ValueError("Could not find two distinct points")
@@ -60,7 +60,7 @@ def refresher():
             (d1_date, d1_val) = prev
 
             t0, t1 = epoch(d0_date), epoch(d1_date)
-            rate = (d0_val - d1_val) / (t0 - t1)   # $/sec
+            rate   = (d0_val - d1_val) / (t0 - t1)  # $/sec (may be negative)
 
             DEBT_STATE.update(
                 debt_at_record = d0_val,
@@ -70,14 +70,14 @@ def refresher():
             )
 
             print(
-                f"[refresh] {d0_date=}  "
-                f"debt={d0_val:,.2f}  rate={rate:,.2f}$/s"
+                f"[refresh] {d0_date=}  debt={d0_val:,.2f}  "
+                f"rate={rate:,.2f}$/s"
             )
 
         except Exception as e:
             print("Debt refresh error:", e)
 
-        time.sleep(300)      # five-minute cycle
+        time.sleep(300)  # five-minute cycle
 
 threading.Thread(target=refresher, daemon=True).start()
 
@@ -88,9 +88,11 @@ def root():
 
 @app.route("/api/debt")
 def api_debt():
-    now = time.time()
-    elapsed = now - DEBT_STATE["record_time"] - 86400
-    current = DEBT_STATE["debt_at_record"] + DEBT_STATE["rate_per_sec"] * elapsed
+    now        = time.time()
+    # subtract 12 h guard so we never “project into the future” for the
+    # current calendar day, yet keep full projection when record is >1 day old
+    elapsed    = max(0.0, now - DEBT_STATE["record_time"] - 12*3600)
+    current    = DEBT_STATE["debt_at_record"] + DEBT_STATE["rate_per_sec"] * elapsed
     return jsonify(
         startingDebt   = current,
         ratePerSecond  = DEBT_STATE["rate_per_sec"],