File Name Prefix Date Dir First (Mikey)

This node is close enough to Mikey Nodes' plain FileNamePrefix that the two are worth reading as a pair - same four inputs, same single string output, same job of building the filename_prefix string that ComfyUI's core Save Image node expects. The difference the name is pointing at is folder ordering: which comes first in the resulting path, the date directory or your custom directory.

What it does

Like its sibling, it's a pure string-assembly node with no image inputs and no side effects of its own - it produces one filename_prefix STRING that you wire into the core Save Image node's filename_prefix widget (right-click, convert to input, connect). The four controls:

• date (true/false, default true) - include today's date in the prefix.
• date_directory (true/false, default true) - put the output in a folder named for today's date rather than just prefixing the filename with it.
• custom_directory - your own subfolder, on top of whatever the date logic produces.
• custom_text - free text appended into the final prefix string.

Being honest about what's unverified

The pack's README doesn't document either FileNamePrefix node by name - both only appear in an unexpanded "Additional Nodes" list, grouped together as a pair with no further detail. Going purely off the class name, "Date Dir First" almost certainly means the date-based folder gets placed ahead of your custom directory in the resulting path (2026-08-04/my_project/ rather than my_project/2026-08-04/), while plain FileNamePrefix presumably does the reverse or handles it differently. I can't confirm the exact ordering behavior from the schema alone - if the specific folder structure matters for how you organize output, the fastest way to know for certain is to drop both nodes on a test canvas with identical inputs and compare the two strings they produce before wiring either one into a real save chain.

Installing

Ships with the full Mikey Nodes pack, same as every other node here - ComfyUI Manager, search "Mikey Nodes," install, restart, or cd ComfyUI/custom_nodes && git clone https://github.com/bash-j/mikey_nodes followed by a restart. No models or extra dependencies for this node; it's string logic only.

Common issues

• Picking the wrong one of the two nodes for your folder structure. Since the two nodes only differ in ordering (as best as can be inferred from the name), it's easy to grab the wrong one and end up with a folder tree that doesn't match how you organize your other output. Test both before committing a large batch run to either.
• Empty prefix strings if nothing is wired. Like its sibling, this node only affects your saves if you actually convert Save Image's filename_prefix widget to an input and connect this node's output to it - leaving it as a static widget means nothing here has any effect.
• Restart required after install. Standard for any new custom node - refreshing the browser tab alone won't register a newly installed pack; restart the ComfyUI process itself.