Countdown Generator (Flask + Jinja)

A tiny two-page app:

• / – a setup form to pick the target date/time and styles.
• /countdown?… – the shareable countdown page, configured entirely from query params.

Quick start

python3 -m venv .venv
source .venv/bin/activate
pip install flask
python app.py
# open http://127.0.0.1:5000/

URL Parameters

• target — ISO-8601 local datetime (e.g. 2025-09-06T12:00)
• title — heading text
• scheme — dark or light
• accent — CSS color (e.g. #ff6b6b or hsl(260 90% 60%))
• fg / bg — text/background colors
• radius — number (px) for rounded corners
• shadow — none|sm|md|lg
• font — CSS font-family string
• millis — 1 to show milliseconds
• rounded_unit — none|minutes|hours|days (rounds to nearest)

Example

/countdown?title=Ignacio%27s%20Trip&target=2025-09-06T12:00&scheme=dark&accent=%238b5cf6&radius=20&shadow=lg&font=system-ui&millis=1

Notes

• The generator reflects any params back into the form, so you can tweak and re-generate links.
• No external assets required. Everything is pure HTML/CSS/JS with Flask+Jinja.
• The countdown runs with requestAnimationFrame and updates at ~60Hz (with ms on if enabled).
• If no target is provided, /countdown redirects to /.