No amount of time is the right time.. There's not a certain amount of time that's right.
I believe in feelings though and when you meet someone that makes your smile bigger than ever and your eyes wider then that's the right time. Whether it's weeks or months or even years after the relationship ended, you'll know when the right time is when you meet someone that makes you feel lucky that it didn't work out with anybody else before.
I'll be honest, as my relationship was slowly dying down and fading into the shit storm it became, I still held hope out for it even when the other person didn't believe in it or me anymore and I know me clinging onto the rubble of the relationship was because I was scared to feel that way for anybody else, I hate feeling vulnerable so putting myself in that situation again with someone else didn't feel right.
You can go from feeling safe and secure around someone to feeling like you don't know them anymore and that's absolutely fine - people change, I changed and matured whilst some people just stuck to what they do best and you can NEVER make people change, they'll only change if they want too.
If somebody makes you feel so goddamn happy then go for it because the person that deserves happiness is ALWAYS you! There's no need to keep grieving over a relationship that obviously isn't going to work out again, be happy with someone that makes you feel like you're their world.
And ALWAYS remain dignified.