Backing up individual directories

[2babies=tired]

I only want to have to back up the avatar, attachments, profile pics, themes, smileys etc once a month, but backup the important files twice a week. I'm just not sure which files definitely need backing up more regularly.

Would it be wise to regularly back up the following when doing a twice weekly backup?

Sources
settings_bak.php
settings.php
index.php
SSI.php

Is there any others I should ensure get backed up with these files/dir please?

Many thanks

2babies=tired

[Arantor]

You only need to back any of those up (as well as the Themes directory) if you install any mods. If you don't install any mods or themes, the files shouldn't be changing in those folders.

[2babies=tired]

so if my board crashed tomorrow and I didn't have a backup for say 28 days, won't I lose information of the past 28 days? 

Or is that just the database that I need?

[Arantor]

The database contains all that information, and *that* should be backed up twice weekly.

The files only contain the code, which means to say if you don't add any mods or themes, the code won't change.

[2babies=tired]

Great thank you very much