I Spent Weeks Building a Clock for Global Stock Market Hours
Source: Dev.to
And a 20‑Year Trader Didn’t Laugh
We live in the era of AI agents and overnight startups, “10x your productivity” threads, full‑blown trading platforms with heat maps, AI signals, and blinking dashboards.
And I built… a clock.
A global stock‑market clock.
It turned out to be much more complicated than I expected.
TL;DR
I built a simple global stock‑market‑hours tracker because I was tired of noisy trading dashboards. It became a lesson in time zones, scope creep, and why shipping beats perfection.
It Started With a Simple Question
Last year my son asked for a trading account. After some evaluation (and strict limits) I opened one for him. I tried mentoring – mixed results – but at least I convinced him not to start with crypto.
One thing became obvious immediately:
Markets open and close.
If you don’t know when, you’re already behind.
He still has some money left in his account, which I consider a success metric.
“Surely This Exists”
I just wanted to know:
- Are US markets open right now?
- When does Frankfurt close?
- How much time do I have before the chaos begins?
Simple questions, surprisingly messy answers.
Yes, there are websites and apps that list trading hours, and there are advanced platforms that bundle everything. But I wanted something different:
- A clean global overview – open / closed / opens soon / closes soon
- A countdown timer
- One small extra: major indices next to each exchange
Not a trading terminal. Not every finance tool needs to be another Bloomberg terminal. 📈
So I built TradeDialer – a global stock‑market‑hours tracker with real‑time countdowns and live indices.
The First Version
There’s a story about a first version built for my son:
- I vibe‑coded it.
- I used it.
- I published it.
- I forgot about it.
Classic side‑project vibe. 😴
Then I Reopened It
In January I met a friend from the Prague dev community. We talked about AI, shipping fast, vibe coding, and I opened the app to show him.
It was broken: time glitches, wrong market states, edge cases everywhere. It looked simple – it wasn’t.
So I started fixing it: evenings, nights, “just one more bug.” You know the pattern. 🙄
“It’s Just Time.”
Narrator: It was not just time.
I’ve worked in software for years – including finance – so I confidently thought:
“Handling time zones and trading hours? Weekend project.”
Here’s what “just time” actually meant:
- Global daylight‑saving chaos
- Exchange‑specific holidays
- Partial trading days
- Index hours ≠ exchange hours
- API quirks
- Rate limits
- Caching strategies
- Synchronization edge cases
- Desktop vs. mobile version
Time is simple—until it spans the planet.
Backend Confidence vs. Frontend Humility
I’m a backend developer, so I chose Kotlin + Spring Boot + microservices and containerised everything.
Frontend? Let’s call it:
- Vibe coding
- Reviewing
- Refactoring
- Learning the hard way
Respect to frontend engineers. 👍
Infrastructure (Because Developers)
I like the proper setup:
- Terraform
- GitHub Actions
- AWS (ECS + CloudFront)
Fully automated deployment… for a clock. Yes, I see the irony.
The “Reality Check” Moment
I showed the app to a friend who has been trading for decades. He didn’t laugh. He didn’t say “this is useless.” He calmly opened professional platforms with heat maps, real‑time flows, advanced dashboards, and enough information to overload three brains.
I looked at him and said:
I’m not fighting those platforms. I’m building for the person who opens a trading app and feels cognitively exhausted – too many colors, too many numbers, too many blinking things.
Maybe you don’t need another dashboard. Maybe you just need to know:
- Is the market open?
- When does it close?
- What’s the index doing?
That’s it.
From This
Into This
## What I Learned So Far
- Small tools are never small.
- Time is harder than distributed systems sometimes.
- Estimation is fiction.
- AI helps a lot — but experience still matters.
- Perfection is the enemy of shipping.
At some point, you push it live.
## The Result
**TradeDialer** – a global stock‑market‑hours dashboard with:
- Live open/close countdowns
- Major indices
- Clear filtering (active, sleeping, opens soon, closes soon)
- Minimal cognitive load
No predictions.
No hype.
No trading signals.
Just time.
## Maybe You’re That Person
If you’ve ever Googled:
> “Is NASDAQ open right now?”
or you feel slightly overwhelmed by full trading dashboards…
Maybe this is for you.
I’m not trying to replace professional platforms. I just wanted clarity.
If that resonates, you can check it out here:
👉
And if you think it’s useless — tell me why.
That’s how small tools get better.
*But I did spend weeks building a very sophisticated clock. ⏰*