Based on the amendments to Japanese patent law effective April 1, 2009, the time frame for filing a divisional patent application after receiving the Decision of Rejection was revised from “30 days from the transmittal of the Decision of Rejection” to “four months from the transmittal of the Decision of Rejection”, even if an appeal is not filed.

The following is the time frame that a divisional application can be filed:
Time frame for filing a divisional application