First you need to enable the mod\_expires module:
```apacheconf
a2enmod expires
```
Next add this to your configuration:
```apacheconf
ExpiresActive On
# Set Expires header to current time by default
ExpiresDefault A0
ExpiresDefault "access plus 30 days"
ExpiresDefault "access plus 7 days"
ExpiresDefault "access plus 1 day"
```
Now restart Apache:
```apacheconf
$ sudo /etc/init.d/apache2 force-reload
```
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