Czy następstwo czasów występuje w takich zdaniach

Dzień dobry

Mam małą wątpliwość odnośnie następstwa czasów i w ogóle poprawności zdania.

"I told you it will be a beautiful day when Tom come back"

Czy coś takiego ma sens czy powinno tam być jednak "was" w tym przypadku ?

Sens jest taki że obecna rozmowa dotyczy wspomnienia rozmowy z przeszłości - sprzed pół roku powiedzmy.
Dziś pisze do tej samej osoby - "a widzisz, mówiłem Ci że to będzie piękny dzień kiedy Tom wróci do nas". (bo ja wierzyłem że on żyje i wróci)

Będę wdzięczny za korekty i uwagi.
Dziękuję ;)

comes back
Ja bym napisala :
See? I told you that it would/will be a beautiful day when Tom comes back to us.

"I told you it would be be a beautiful day when Tom came back"

Tom's coming back was meant to overlap (or be simultaneous with) its being a beautiful day.
Cf: It will be a beautiful day when Tom comes back.
In both cases the verb in the subordinate when-clause is relative to (and temporally subordinate) to the situation presented in the main it-be-clause.

would be be
You must do better ;-)

@Jansky

I know how that works by the book. What you wrote is by the book. However, in the informal conversation with my friend when we are both happy that Tom is alive, using comes and will wouldn't be such a big crime. It would emphasize that we are enjoying this present moment when he returns. Or am I terribly wrong?

No, you are not terribly wrong. You are just a little bit wrong when you write (typing is writing, isn’t it?) that that’s how you would say it (again?) should you be given the opportunity of saying it in the same circumstances.

You are just a little bit wrong

That is good. It makes me feel that the language I use is for me, not me for the language. I like to feel things rather than overanalyze them, language included. :)
Thank you for your input.

Wysłałem jego posty do moderacji. Lukar da mu w końcu bana i się skończy. ;-)