Copy observation to blank observations within specified time frame

[Gerwin Pieter Colje]

Dear all,

I am looking for a solution to copy an announcement date to all dates within a specified time frame. This time frame ranges from -250 days to +1 day to the announcement date. My data is organized as panel data and looks like:

ncusip	Date	AnnouncementDate
10	20-7-2017	.
10	21-7-2017	.
10	22-7-2017	22-7-2017
10	23-7-2017	.

The problem is each nscusip might have more than 1 announcement dates. A command such as: bysort ncusip: egen AnnouncementDate2 = mean(AnnouncementDate) would not work therefore unfortunately. Are there any ideas to solve this problem?

Kind regards,

Gerwin Coljé

[Gerwin Pieter Colje]

Dear all,

I think I have made a solution with this loop:

forvalues i=-1(1)250 {
by permno: replace DateAnnounced1 = DateAnnounced[_n+`i'] if DateAnnounced1==.
}