Fantastic H3 Filename Prefix

Some ComfyUI bugs are elaborate. This one is just dumb. Save nodes - VideoHelperSuite among them - only expand date tokens like %date:yyyy-MM-dd% when you type them straight into the save node's own widget. Pipe that same prefix through a string node, a switch, a Set/Get, or basically any wiring, and the token arrives verbatim. You end up with a folder literally named %date:yyyy-MM-dd%, and no amount of _00001 counter is going to make that feel organized.

Fantastic H3 Filename Prefix is a tiny node that exists to kill that problem. It builds the prefix from parts, resolves the date itself on every run, and hands the save node a plain string that survives any amount of wiring. It ships in the same pack as the Fantastic H3 Prompt Builder and the Media Loader - the pack that does guided prompt writing for MiniMax H3 - but this node is useful for any video or image workflow with a dated-folder habit.

How it works

The node does the date expansion for you. The pack's source shows it re-evaluates on every execution (its IS_CHANGED returns the current time, so ComfyUI's caching can't hand you yesterday's date), then joins your folder, subfolder, date folder, and filename into one path.

The four inputs that matter

• folder - the folder under ComfyUI's output directory. There's a 📁 Browse… button that walks your output directory (click to enter, .. to go up, Create to make a new folder on the spot), or you can type a path.
• subfolder - optional extra levels, created if missing. Ref2V or client/act2 both work.
• date_folder - off, or a dated folder in one of seven formats: YYYY-MM-DD, YYYY_MM_DD, YYYYMMDD, YYYY-MM, YYYY/MM/DD, YYYY-MM-DD_HH-MM. The label you pick is what gets saved in the workflow, so it means the same thing tomorrow.
• filename - the start of the file name. The save node still appends its own counter.

So folder MiniMaxH3, subfolder Ref2V, date YYYY-MM-DD, filename vid gives you MiniMaxH3/Ref2V/2026-08-07/vid_00001.mp4. You can also use date tokens inside subfolder and filename (%date:hhmm% becomes 1409), and both dialects - ComfyUI %date:...% and bare strftime - are accepted.

The one output

filename_prefix - a plain STRING. Wire it into the save node's filename_prefix input. If that shows as a widget rather than an input, right-click and choose Convert widget to input, same as you would for a prompt.

Install

Through ComfyUI Manager, search for "Fantastic H3 Prompt Builder". Or:

cd ComfyUI/custom_nodes
git clone https://github.com/Adudeguyman/ComfyUI-Fantastic-MiniMaxH3-PromptBuilder

Then restart ComfyUI completely - a browser refresh won't register nodes. No model downloads; the only dependency is PyAV (av), which ComfyUI core already requires. The node appears under conditioning → video_models.

Troubleshooting

If the date looks stale, remember the node re-evaluates each run - the value you see on the canvas isn't the value sent at queue time. And the one real trap: it only helps when you wire its output into the save node. Type a %date: token into the save widget directly and you're back in widget-only-expansion land, which is fine - the node just isn't involved.