Date format for "When" parameter is unclear

[strogiyotec]

Good day. Let's say I want to add a new event into my calendar . I use gcalcli add command and it asks me for a date using When: hint. However it's unclear for me which date format it expects.I wrote 10/05/20 12:30pm and thought that it will choose 10th of May but gcalcli parsed it as 5th of October. In order to understand the format I had to look through the source code and find that it uses dateutil.parser.parse method. I think it would be better to have some sort of hint about date format something like this

When(ex. yyyy-MM-dd hh:MM(am/pm)):

What do you think ? If it's ok I could contribute and implement it .