Format of return values from Last-Rain-extension

[didier....@gmail.com]

Hi

I have installed the last-rain extension which give me 2 return values "last_rain" and "time_since_last_rain"

In the Github documentation, I can see:

Result is returned as a ValueHelper so standard Weewx formatting is available eg $last_rain.format("%d %m %Y")

Could you say me where I can defined this fomat? Is it in weewx.conf? or elsewhere?

Many thanks for your help

Didier