### 14.5.5.4 TimedRotatingFileHandler

The `TimedRotatingFileHandler` class, located in the `logging.handlers` module, supports rotation of disk log files at certain timed intervals.

class `TimedRotatingFileHandler`( | filename [,when [,interval [,backupCount]]])

  Returns a new instance of the `TimedRotatingFileHandler` class. The specified file is opened and used as the stream for logging. On rotating it also sets the filename suffix. Rotating happens based on the product of when and interval.

  You can use the when to specify the type of interval. The list of possible values is, note that they are not case sensitive:

  Value | Type of interval
  --- | ---
  S | Seconds
  M | Minutes
  H | Hours
  D | Days
  W | Week day (0=Monday)
  midnight | Roll over at midnight

  If backupCount is non-zero, the system will save old log files by appending extensions to the filename. The extensions are date-and-time based, using the strftime format `%Y-%m-%d_%H-%M-%S` or a leading portion thereof, depending on the rollover interval. At most backupCount files will be kept, and if more would be created when rollover occurs, the oldest one is deleted.

`doRollover`( | )

  Does a rollover, as described above.

`emit`( | record)

  Outputs the record to the file, catering for rollover as described above.