Spotting Minimum-Balance Days

A household account can look fine on the 1st, thin on the 12th, and fine again the morning after payday. The month’s income and the month’s bills did not change between those days. The order did.

FlowBooks Home is built to show that order. You plan income and expenses on the days they happen. The calendar keeps a projected balance for each day and marks the minimum-balance days, the days when that projection is at its lowest, before you get there.

What the projected balance is

The projection starts from the balance you enter for the plan. From there it walks the month one day at a time:

• planned income on a day increases that day’s ending balance
• planned expenses on a day decrease it
• a balance adjustment on a day changes it by the amount you record
• the ending balance carries into the next day

The number on a day is the balance the plan expects at the end of that day. It is not a feed from your bank, and it does not move when a card is swiped unless you put that spending on the calendar.

Because each day depends on the day before it, a bill early in a gap lowers every day until the next deposit. That is why two months with the same totals can feel different. The low point moves when the dates move.

What a minimum-balance day is

Inside the month, FlowBooks Home finds the lowest projected ending balance. Every day that ends on that same figure is a minimum-balance day. The calendar marks those days, and the month summary shows the minimum balance itself.

A few things follow from that:

• It is the low point of the plan you entered, not a threshold you set. You do not type “warn me at this amount.”
• There can be more than one. If the balance stays at that low figure across a weekend with nothing planned, each of those days is a minimum-balance day. The tight window is the whole stretch, not a single square.
• A payday often is not the minimum-balance day. The deposit raises the ending balance. The day before the deposit, after the bills in the gap have come out, is the day that is usually under the most pressure.
• The closing balance of the month can look healthy while a minimum-balance day in the middle is the one that matters. The last day of the month is only the low point when nothing earlier went lower.

Read the mark before the month arrives. The point of the forecast is to see the tight day while you can still move a purchase, shift a transfer, or set aside the bill that lands in the gap.

How to find the tight day

1. Enter the balance you are starting from and the date it applies to.
2. Add the income you expect, on the days it should arrive. For a biweekly paycheck, that means each payday on its own date. The guide to biweekly paycheck timing covers three-paycheck months, rent on the 1st, and the run-up to the 15th.
3. Add the bills and other spending you already know about, on the days they leave. Include the small drafts. A day looks ordinary until the one you forgot is sitting on it.
4. Look for the minimum-balance mark, and read the projected ending balance on that day.
5. Step backward through the days before it. The items on those days are what produced the low point. Sometimes the fix is the day itself. Often it is a bill two or three days earlier, or a paycheck that arrives the next morning.

Couples sharing one checking account can put both pay schedules and the shared bills on the same calendar. The minimum-balance day is then a property of the shared plan, which is the question the account actually has to answer.

If you have been tracking the same dates on paper or in a spreadsheet, you already have the list. The difference is that the projected balance and the minimum-balance mark are calculated from that list instead of estimated by scanning it.

When the plan and the month disagree

A forecast goes stale when a real amount shows up that the plan did not have. A refund, a fee, a check that cleared for a different number, a transfer between accounts: record a balance adjustment on the day it belongs. Add a note on that day so the reason is still there when you look back.

An adjustment is a one-time correction. It is not a second copy of a bill you have already planned. If the bill itself changed, change the planned item. If the date slipped, move it. Then read the minimum-balance days again. Moving one bill across a payday can move the low point from the day before payday to somewhere much quieter, or it can reveal that a different day was the real constraint.

Notes are for the context the amount does not carry: “paid early,” “reimbursement still coming,” “this draft failed and will retry.” The projected balance does not guess at that. The note keeps it attached to the day.

A short reading of a gap

This is an illustration of how to read the calendar, not a real account and not a sample balance from the product.

Say the plan has a paycheck on the 6th and the next one on the 20th, with a loan payment on the 15th and groceries you intend to buy on the 12th. Nothing else is planned between the 6th and the 20th.

The projected balance steps down on the 12th and again on the 15th, then sits there until the 20th, when the paycheck arrives. The lowest ending balance is on the 15th through the 19th, so those days are the minimum-balance days. The 20th looks better because of the deposit. The question “are we all right this month?” is answered on the 15th, not on the 20th and not on the final day of the month.

If you then add a bill on the 18th that you had left off, the low point moves to the 18th and 19th and the minimum balance is lower. That is the forecast doing its job: the day gets tight on the calendar before it gets tight in the account.

What this does not do

FlowBooks Home does not connect to a bank, watch a live balance, or send an overdraft warning after the money has already left. It does not do envelope or category budgeting. It is not full small-business accounting. That is FlowBooks Business.

Home is the household calendar, $15 a year. You sign in with email and subscribe inside the app. Billing, cancelling, and what to do with a promo code you already have are explained on the FlowBooks Home page. Checkout does not take a promo code. If you have one, you apply it on the subscription screen after you sign in.