Loan / Mortgage Payment Projector
Monthly loan payment dates, rolled to banking days when they fall at a weekend.
Written and maintained by Paul Clark, Redmoon Software · Rules last verified
These calculators are for informational purposes only and do not constitute legal, financial, or professional advice.
How the Loan / Mortgage Payment Projector works
The Loan / Mortgage Payment Projector lists the dates a monthly loan payment falls due and, where a due date lands at a weekend or a public holiday, the banking day it will actually move to. Enter the first payment date and how many payments to project.
Monthly recurrence is not the same as a fixed interval, and that is the distinction this tool exists to handle. A payment due on the 31st recurs on the 31st — except in the months that have no 31st, where it clamps to the last day. A fixed 30-day interval would drift a few days earlier every month and be a week out by autumn. The calculator recurs on the day of the month and clamps at month end, which is how loan notes are actually written, and it reports how many of the projected payments land on a day the banking system is closed.
Two caveats. Lenders differ on which way a non-banking due date moves: this calculator rolls forward to the next banking day, which is the common treatment for ACH debits, but some agreements pull the debit backward to the preceding banking day instead, and many treat a payment received inside a grace period as on time regardless. Check the note. And this projects <em>dates only</em> — there is no amortisation here, no principal and interest split, no balance. If you need to know how much of each payment is interest, that is a different calculation and this tool does not do it.
Worked example
A loan with its first payment on Saturday, 31 January 2026, projected over six months, recurs on the 31st where one exists and clamps to the last day where it does not — so February falls on the 28th and April on the 30th. Three of the six due dates land at a weekend, and the calculator shows both the contractual due date and the banking day the debit will actually hit, which is the pair that matters when you are timing a deposit to cover it.
Frequently asked questions
Why does the date change in February?
Because a payment due on the 29th, 30th or 31st cannot fall on that date in every month, so it clamps to the last day of the shorter month and returns to its normal day afterwards. This is standard loan-note behaviour and it is why a monthly schedule is not the same as a 30-day interval — the interval version drifts permanently while the monthly version self-corrects.
Does a weekend due date mean the payment is late?
Usually not. Most notes provide a grace period, commonly ten to fifteen days, within which a payment is treated as on time and no late fee applies. What the weekend affects is when the money actually leaves your account, which matters for making sure the funds are there. Check the note for both the roll convention and the grace period — they are separate provisions.
Does this show principal and interest?
No — it projects dates only. There is no amortisation schedule here, no split between principal and interest and no running balance. Use it to plan cash flow around when payments fall, and an amortisation calculator for what each payment is composed of.
What this calculator does not do
A limitation you know about costs far less than one you find after the deadline. These are the specific things this tool cannot work out for you.
- It projects payment dates, rolling them to banking days. It does not compute interest, amortisation or a payoff balance.
- Whether a payment falling on a weekend is taken before or after it is a lender convention; the tool rolls forward.