This law is binding on Persian believers

"…the Universal House of Justice instructs us to say that according to its ruling, the law of the Kitáb-i-Aqdas that the lapse of time between engagement and marriage should not exceed ninety-five days, is binding on Persian believers wherever they reside, if both parties are Persian. This law is not applicable, however, if one of the parties is a western believer."

-Lights of Guidance (second part)

https://bahai-library.com/hornby_lights_guidance_2&chapter=3/