Information about the Galaxy S9's announcement date comes from Evan Blass's Twitter account, @evleaks. He often gives leaked information about smartphones that have not been announced officially.
According to a C-level executive at a major casemaker, the go-to-market schedule for Galaxy S9 / S9+ is as follows:— Evan Blass (@evleaks) 16 Januari 2018
Launch - 2/26
Pre-orders - 3/1
Ships/releases - 3/16
Evan claims to get that information from top level executives of casing makers. Samsung Galaxy S9 will be announced on February 26, while the pre-order starts on March 11, 2018. Samsung is expected to start shipping Galaxy S9 on March 16, 2018.
The timing of this announcement is in line with the statement from the previous Samsung. The South Korean firm has confirmed the Galaxy S9 will be announced at Mobile World Congress (MWC), Barcelona, Spain. The MWC will run from February 26 to March 1, 2018.
Samsung's flagship launch this year will be different, as it usually makes its own special event. But this year, the company actually announced the Galaxy S9 in MWC.