A date string tool built with Gemini should save 45 seconds a week
Tired of typing new Date().toISOString() and doing timezone math by hand, they built a small tool with Gemini, which added obscure date formats and random historical events along the way.
Done withGeminiSpotted· by HN user kbst· Oct 22, 2026
Time saved
About 45 seconds a week (their estimate)
Result
Comes with bonus physics trivia
“By my estimates, this tool should save me about 45 seconds of work per week!”
Spotted: found in the wild. Details are as reported by the source above and have not been independently verified.
What they did
Tired of typing out new Date().toISOString() in the dev console and doing timezone conversions in their head to get ISO 8601 date strings, they built a small tool with Gemini.
How it went
Gemini helped complete it with obscure date string formats, random historical events, and other physics trivia thrown in. By their own estimate, the tool should save about 45 seconds of work per week.
Try it yourself with Gemini
Help me build a small web tool for generating ISO 8601 date strings: let me pick a date and timezone, show the correct toISOString() output, and throw in a fun extra for each date, like a historical event or trivia fact that happened on it.
A starting prompt written by Agents in the Wild. Fill in the [brackets], and check what the agent does before it sends, pays for or deletes anything.
To keep up with industry and tech news, the writer built a free-tier Google Cloud Run job pulling Google News RSS feeds. Gemini picks which articles match their criteria and triggers a summary email.
Auto-placed crop zones with perspective correction and edge snapping, in the browser. It wasn't right on the first try, but building it was much faster than hunting for an existing tool.
Escape the algorithm's repeats. ChatGPT and Gemini helped a former web designer build a generator that pulls 1 or 2 lesser-known songs from each of their top artists, in a couple of evenings.
Six AI workers, two each on Claude, Codex and Gemini, were set loose to build a SQLite-like engine in Rust. It passed 64 queries of a 1,000+ query suite, with slop like redundant buffer copies and no concurrency.
Amazon support couldn't figure out the URL for an account question and wanted to escalate with a phone call instead. Gemini gave the URL and explained what was needed in one reply. ChatGPT got it right too.
A T-shirt like the Asket tee at its old $50 price, and shorts to match an old pair. Grok invented a few review claims on the way, but both picks turned out right.