moved some hard-coded dates to top of calc.py for ease of use in multiple functions, but also just for code readability, they are more like constants than variables. Code now works out key_dates for use in dealing with future bills / next steps

bills.py

@@ -291,7 +291,7 @@ def get_growth_value( bt, bill_type ):
 # and I didn't want to input 12 of them at the same price), and it always
 # occurs for future bills
 ################################################################################
-def process_bill_data(bd, bt, bf):
+def process_bill_data(bd, bt, bf, key_dates):
     # this maps a bill id to a freq id (e.g. bill #34 - has a frequency of #2 (which might be quarterly)
     bt_id_freq = {row["id"]: row["freq"] for row in bt}
     bt_id_ann_growth_avg = {row["id"]: row["ann_growth_avg"] for row in bt}
@@ -495,3 +495,4 @@ def calc_future_totals(bill_info, bill_types):
             # had to round to 2 decimal here to get sensible totals
             total[bt['id']][yr] = round( total[bt['id']][yr], 2 )
     return total
+

calc.py

@@ -5,6 +5,15 @@ from defines import END_YEAR
 # GLOBAL CONSTANTS
 LEASE = 0
 
+# Dates that don't change
+car_balloon_date = datetime(2026, 11, 15)
+new_fin_year_25 = datetime(2025, 7, 1)
+new_fin_year_26 = datetime(2026, 7, 1)
+end_date = datetime(END_YEAR, 4, 15)
+school_fees_date = datetime(2025, 12, 5)
+mich_present_date = datetime(2026,10,15)
+first_pay_date = datetime(2025,1,8)
+
 def bill_amount_today(finance, day, bill_data, bt_id_name, total ):
     amt=0
     day_str = day.strftime("%Y-%m-%d")
@@ -100,8 +109,6 @@ def calculate_savings_depletion(finance, bill_data, bill_type):
     D_has_quit = False
     D_quit_year = 0
     claim_tax_on_leave = False
-    new_fin_year_25 = datetime(2025, 7, 1)
-    new_fin_year_26 = datetime(2026, 7, 1)
 
     # Constants for interest calculations
     annual_interest_rate = Interest_Rate / 100.0
@@ -109,7 +116,6 @@ def calculate_savings_depletion(finance, bill_data, bill_type):
 
     # main loop range -- start from now, and simulate till D is 60 (April 2031)
     current_date = datetime.today()
-    end_date = datetime(END_YEAR, 4, 15)
 
     # work out which bill_types relate to future bills
     for bt in bill_type:
@@ -151,11 +157,6 @@ def calculate_savings_depletion(finance, bill_data, bill_type):
     depletion_date = None
     savings_per_fortnight = []
     
-    # significant dates that are non-changeable
-    school_fees_date = datetime(2025, 12, 5)
-    car_balloon_date = datetime(2026, 11, 15)
-    mich_present_date = datetime(2026,10,15)
-
     # significant dates - but who knows when? :)
     overseas_trip_date = datetime.strptime( finance['Overseas_trip_date'], "%Y-%m-%d")
     mark_reno_date = datetime.strptime( finance['Mark_reno_date'], "%Y-%m-%d")
@@ -360,3 +361,26 @@ def calculate_savings_depletion(finance, bill_data, bill_type):
 
     return depletion_date, savings_per_fortnight, current_savings
 
+################################################################################
+# work out the date D quits and when we own the car, so we can then use it to
+# handle future bills
+################################################################################
+def calc_key_dates( finance ):
+    key_dates={}
+    now = datetime.today()
+    # this will be 0 to 13 days - how far into this fortnights pay cycle are we now
+    days_in_pay_fortnight= ( now - first_pay_date ).days % 14
+
+    # add 1 less fortnight than we continue to work, then add rest of pay cycle (14-days_in_pay_fortnight)
+    key_dates['D_quit_date'] = (now+timedelta(weeks=2*(finance['D_Num_fortnights_pay']-1))+timedelta(days=(14-days_in_pay_fortnight))).strftime('%Y-%m-%d')
+
+    # use lease date
+    if finance['Ioniq6_future'] == LEASE:
+        key_dates['D_hyundai_owned'] = car_balloon_date.strftime('%Y-%m-%d')
+    # use buyout date
+    else:
+        key_dates['D_hyundai_owned'] = finance['Car_buyout_date']
+
+    print( f"kd={key_dates}" )
+    return key_dates
+

main.py

@@ -1,6 +1,6 @@
 # main.py
 from flask import Flask, render_template, request, redirect, url_for, Response, jsonify
-from calc import calculate_savings_depletion
+from calc import calculate_savings_depletion, calc_key_dates
 from db import init_db, get_finance_data, update_finance, get_budget_data, insert_cset, get_comp_set_data, get_comp_set_options, get_bill_freqs
 from db import get_bill_data, new_bill, update_bill_data, delete_bill
 from db import get_bill_ui, save_ui
@@ -145,14 +145,20 @@ def update():
 
 @app.route('/bills')
 def DisplayBillData():
+    finance_data = get_finance_data()
+    # work out when D quits, when car is owned
+    key_dates = calc_key_dates( finance_data )
     bill_data = get_bill_data("order_by_bill_type_then_date")
     bill_types = get_bill_types()
     bill_freqs = get_bill_freqs()
     bill_ui = get_bill_ui()
-    bill_info=process_bill_data(bill_data, bill_types, bill_freqs)
+    # take bill data, AND work out estimated future bills - process this into the bill_info array, 
+    bill_info=process_bill_data(bill_data, bill_types, bill_freqs, key_dates)
+    # get an array of the total costs of bills each year - purely cosmetic (using bill_info)
     total=calc_future_totals(bill_info, bill_types)
+    # update/re-get bill_data now that new estimated bills have been added
     bill_data = get_bill_data("order_by_bill_type_then_date")
-    return render_template('bills.html', bill_data=bill_data, bill_types=bill_types, bill_freqs=bill_freqs, bill_ui=bill_ui, this_year=datetime.today().year, END_YEAR=END_YEAR, total=total )
+    return render_template('bills.html', bill_data=bill_data, bill_types=bill_types, bill_freqs=bill_freqs, bill_ui=bill_ui, this_year=datetime.today().year, END_YEAR=END_YEAR, total=total, key_dates=key_dates )
 
 @app.route('/newbilltype', methods=['POST'])
 def InsertBillType():