# [J], 32 bytes

    [:*/24 60 60>_2".\_6{.'00000',":

[Try it online!][TIO-k7215968]

[J]: http://jsoftware.com/
[TIO-k7215968]: https://tio.run/##ZY8xCwIxDIX3@xWhS1HOmqb2aArnIjg5uSrcIB7i4g/wx9d6ODSxpMOD9768PItxdoYxg4UeEHL9GweH8@lYLnm9pR0MWGc/kXHXaXg7i99ne5PLqrvfHi/wMMIM2Ir4U7ioQSjmrrV6FEkfuTV7mfXMrZmCDFOQaQoyTuF/uVqPqAogqgqICkIxqRoxqR4xqSIxyUtYM1gzWDN4YehzK6V8AA "J – Try It Online"

Prepend '00000' to the stringified int, take the last 6 `_6{.`, format them in groups of 2 `_2".\`, and make sure all chunks are in the correct range.