I've seen lot of people struggling in finding a way to hide the script name when installing their Yii Application. In an Apache environment everything is well documented in this wiki article, but for those who are running their app on a Windows Server machine there are no hints.
Countries sometimes change their laws pertaining to time zones and daylight saving times. This means that GMT+2 can be a different time this August compared to last August! However, by using php's DateTime class (instead of timestamps), we can do both "format" and "time zone" conversions on a single DateTime object (only 2 lines of code) for date, time, timestamp and datetime types - while php takes care of nightmares such as current and historical time zones and daylight saving times.
A big problem I've hit with the Yii-Bootstrap extension is that all AJAX requests are initializing Bootstrap because of preload. This is a huge waste of resources, especially when using AJAX-based file uploaders that split the file into chunks. Large file uploads using that method could be initializing bootstrap hundreds of times.