fileNamePattern = "/myApp-log.%d{yyyy-MM}.log" //Rollover at the beginning of each month, file format: myApp-log.2016-11.log
fileNamePattern = "/myApp-log.%d{yyyy-ww}.log" //Rollover at the first day of each week. Note that the first day of the week depends on the locale.
fileNamePattern = "/myApp-log.%d{yyyy-MM-dd_HH}.log" //Rollover at the top of each hour.