There is no time limit for filing informal complaints
Confront the alleged offender advising him/her to stop and that continuation of the behavior will result in a formal complaint action. The EO office, co-worker, or chain of command can intervene on your behalf to help resolve the issue.
The initial contact with the EO office must be within 45 days of the date of the matter alleged to be discriminatory or, in the case of personnel action, within 45 days of the effective date of the personnel action.
The 45 day limit may be extended for reasons outlined in 29 CFR 1614.102 (a) (2).