“Is is possible to be born again without knowing when it happened?”
I was once confronted by an older Christian who wanted to know the exact time and circumstances of my salvation. Apparently he asked many others the same thing. He was convinced the experience of becoming a believer only comes about in one way, and that it is impossible not to know how and when it occurred. If you can’t tell people when it happened, he insisted, it’s because you’re not saved.
That is not what Jesus taught.