Thoughts on transferring my entire IRA allocation to another fund?

I have \~71k in my Roth IRA with Fidelity right now and I’m currently about 100% into VOO.

However, I also max a Roth 457b every year that is 100% in an ishares S&P 500 index, therefore want to diversify by changing my IRA allocations to 100% international funds.

I’m thinking of changing my VOO to FZILX, should I try to time the market when the US market is up and international market is down in relation? What’s the best way to go about it?