time_since and time_at

This is a WeeWX search list extension (SLE) that can calculate when an SQL statement last evaluted true, or how long since it evaluated true.

Example:

<p>It last rained at $time_at('rain>0') ($time_since('rain>0').long_form ago).</p>

would result in

<p>It last rained 20 June 2020 (81 days, 1 hour, 35 minutes ago).</p>

It is possible to use alternative data bindings by specifying it as the second parameter to the time_since and time_at tags.

<p>It last rained at $time_at('rain>0', 'alt_binding') ($time_since('rain>0', 'alt_binding').long_form ago).</p>

Installation

Unfortunately, there is no automated installer for this extension. However, it is very simple to install manually.

1. Put the file time_since.py in your WeeWX user subdirectory. For example, if you used the setup.py installation method, then you would do

   https://raw.githubusercontent.com/tkeffer/weewx-time_since/master/bin/user/time_since.py
   

   Alternatively, if you used the Debian package installer

   cd /usr/share/weewx/user
   sudo wget https://raw.githubusercontent.com/tkeffer/weewx-time_since/master/bin/user/time_since.py
   

2. Add the extension to option search_list_extensions in the skin configuration file skin.conf of whatever skin you are using. When you're done, it will look something like this:

    [CheetahGenerator]
   
        # Possible encodings are 'html_entities', 'utf8', or 'strict_ascii'
        encoding = html_entities
        search_list_extensions = user.time_since.TimeSince
   
        [[SummaryByMonth]]
        ...
   

3. You are then free to use the new tag in the skin. For example, in my copy of the Seasons skin, I have added it to the table in the current.inc module.

   class="data">$time_at('rain>0')<br/>$time_since('rain>0').long_form ago</td>
   </tr> ```