# Questions

> Short answers to common questions about Kettlemark, from safety and file formats to time zones and phones.

[Contents](#contents)

1.  [Home](https://docs-demo.vagejs.com/)
2.  [Docs](https://docs-demo.vagejs.com/docs/)
3.  Questions

## Does Kettlemark change my photos?

No. It only changes file names. The pictures and their stored information stay exactly as they were.

## Is it safe to run on my only copy?

Kettlemark always lets you preview first and keeps a log so you can undo. Even so, keep a backup of photos you can't replace.

## Why were some files skipped?

They have no date taken stored inside, usually screenshots, scans or files saved from chat apps. See [photos without a date](https://docs-demo.vagejs.com/docs/guides/photos-without-dates/).

## The times are off by a few hours. Why?

Some cameras store the time without a time zone. Tell Kettlemark which zone you were in with `--timezone`, for example `--timezone Asia/Kolkata`.

## Can I use it on my phone's photos?

Copy them to your computer first, then run Kettlemark on that folder. It doesn't connect to phones directly.

## Does it work with videos?

Yes, MP4 and MOV files from phones and most cameras.

[PreviousConfiguration](https://docs-demo.vagejs.com/docs/reference/configuration/)