Your child is sixteen. The conversation about colleges has started to creep into Sunday lunches. They mention a city, a course, an aspiration. You smile. Then later, alone, you do the small piece of mental math that makes your chest tighten. The number is bigger than what you have. There are eighteen months between you and the number.
A known expense isn't a surprise
The strange thing about big known future expenses is that they feel like surprises by the time they arrive. Tuition, weddings, a parent's hospital bill, the down payment on a home. You knew they were coming. You didn't quite let yourself look at them.
The expensive part of these moments isn't the bill itself. The expensive part is the fact that you treated the bill like weather instead of like a date. By the time it's three months away, your options have collapsed. By the time it's three weeks away, you're rearranging things in a hurry and paying the rearrangement tax.
Eighteen months is a different kind of number. Eighteen months is a window where small decisions, made calmly, add up to a real amount of money.
Why most apps don't help here
The default view of every banking app and most budgeting apps is backward-looking. Last month you spent $X. Your average is $Y. The dashboard is a rear-view mirror.
A rear-view mirror is the wrong instrument for a known event in eighteen months. You don't need to know what you spent on coffee last March. You need to know what your account looks like in October 2027 if nothing changes — and what the difference is between that number and the number you're going to need.
The timeline in Marvin Money runs forward. You can scroll past the current month, past next month, into next year. Every recurring bill, every salary, every known one-time spend stacks up into a projected balance for each future month. It is occasionally uncomfortable to look at. It is always more useful than today's number.
Putting the bill on the timeline
Add the future expense as a one-time line on the month it'll land. You're guessing — that's fine. Estimate high. The tuition, deposit, books, accommodation, travel, the everything-that-comes-with-it.
The forecast updates. You see the gap.
That number can feel large or small depending on your situation. Either way, it's a real number. Real numbers can be argued with. Vague dread can't.
Where the $770 comes from
You'll fight for it in pieces. Eighteen months is a lot of subscriptions. Eighteen months is a lot of meals out you didn't quite enjoy. Eighteen months is a long enough horizon that even small habit changes accumulate into real cushion.
Marvin will do most of the heavy lifting here. Open chat and ask it directly — "I need to find $770 a month, where should I look?" — and it reads your timeline and comes back with a specific list. Every recurring subscription you're paying for, ranked by amount. Bills that have crept up. The categories where last month ran 30% over your usual. Marvin can show you what you're paying — only you know which ones you actually use. You mark the ones to cut; Marvin updates the timeline.
If you'd rather do it yourself, the same actions live on the timeline directly — tap any recurring bill to skip, pause, or cancel. Marvin's chat is the shortcut, not the only way. Either way the list usually looks like this:
- Subscriptions you don't really use. The streaming services, the apps, the magazine, the storage unit, the gym you don't go to. The honest number here, for most households, is between $50 and $200 a month.
- The "we'll cancel that someday" line. Most households have one — the membership, the service, the thing that auto-renewed last year and you keep meaning to deal with. Today is someday.
- The big-ticket things. The slightly more modest car. The slightly later phone upgrade. Holding the appliance one more year before replacing it. These don't apply every month, but they add real room when they do.
- The transparent line items. Eating out, delivery, the small luxuries. Not eliminated — that's unrealistic and usually backfires. Just dialled down enough that the timeline shows the difference.
Each of these gets dropped onto the timeline as a change — by Marvin if you asked it to, or by you tapping the line. The forecast updates the moment the change lands. The gap shrinks. The October 2027 number starts to look reachable.
What the eighteen months actually buy you
They buy you the option to say yes when the admission letter arrives without flinching. They buy you the option to send your child to the place they actually want to go, instead of the place that the math allows. They buy you the option to not have a conversation in March 2027 that begins with "we need to talk about something."
They also, importantly, buy you the option to keep your savings intact. Most parents in this situation eventually pull from retirement or take a loan. The single biggest predictor of which ones don't have to is whether they started planning eighteen months out instead of three.
If your child is sixteen tonight
The whole sequence, in five minutes:
- Open Marvin chat. Tell it the expense and the date — "my child starts university in October 2027, I'll need about $18,000." Marvin asks if you'd like it on the timeline as a one-time line on that month — confirm, and it lands there along with the projected balance for the day it falls.
- Ask for the gap. "What do I need to save monthly to close it?" Marvin gives you the monthly figure — somewhere around $770 in this example.
- Ask where to cut. "Find the first $200 of that tonight." Marvin reads your timeline and lists every recurring subscription you're paying for, ranked by amount. You spot the two you don't actually use, the plan that could drop a tier, the recurring you'd forgotten about. Tell Marvin which ones to cut — it updates the timeline as you confirm.
- The remaining $570-or-whatever is for next weekend, not for tonight. Pace it.
- Open Marvin Money once a month after that. The dashboard updates on its own — the forecast verdict shifts as your spending lands. You don't need a calendar reminder. You need to look once.
Prefer doing it by hand? Every step above has a manual equivalent on the timeline — scroll forward, tap a future month to add the expense, tap any recurring bill to skip, pause, or cancel. Marvin's chat is the shortcut, not the only way.
Eighteen months is enough to do this calmly. Three months isn't. Tonight is the cheapest version of this conversation you'll ever have.
The discipline of holding onto money longer than you have to is its own small art — why the day the bill arrives isn't the day to pay it. For the moment a kid first enters the picture, see the first kid changes the math.