@John4321 I'm no expert, but the general consensus with regard to timeframes is that you need to be invested for at least 5 years plus.
Of course, it all depends. But as anecdotal evidence, my better half had an SIP throughout 2007, that began in Jan 2007 and ended in Dec 2007. The 2008 market crash happened. Neither added/averaged, nor booked out/redeemed. So possibly the worse way to be doing an SIP. In Jan 2018, the amount in one fund had more than tripled iinm, while in another (an international fund), it had appreciated by 50%.
So my guess is 10 years plus is a good timeframe to have, rather than 5, because it means that you could get in at the worst possible time & still survive. (Based on anecdotal evidence, of course).
One thing you could do is look at the 'Rolling Returns' of various mutual funds at various time frames. That'll help you gauge better the returns that you can expect at different points of the market cycle. (Advisorkhoj has a tool that I feel is easiest to understand). HTH.
Edit: Just realize that it's a gamble. The longer timeframes only reduce the gambling element somewhat, but never completely eliminate it.