As often as needed.
Remember novels like Roots [Alex Haley] that cross something like six generations of people, a few centuries of time. Then get compressed to a two-hour timeframe for the Movie! Obviously, time lapse is crazy important.
Consider from Roots Chicken George:
- We see his conception: His mother Kizzy is raped by her owner, Tom Moore.
- Age 3/4, Kizzy won't tell him who is father is, she just tells him he is the grandson of Kunta Kinte, a great African warrior.
- Age 6, he becomes fascinated with Mingo, the chicken fight trainer.
- Age 12, he is moved in with Mingo to train chickens full time.
- Age 15, he wins [the chicken he trained wins] his first cockfight.
- Age 18, #1 Trainer! Promoted to head trainer by his owner Tom Moore, Mingo is proud of him.
And so on. In six scenes of a few minutes each, we've covered from conception to adulthood and the peak of his power and potential. Tom Moore is promising him freedom, he is making money, admired, etc. (Then it crashes...)
But I don't want to appear lazy or give the impression of a story full of holes.
The key to avoiding that impression is to remember you are still sketching a character arc. The first two scenes set up a devastating revelation for Chicken George later: That his father is Tom Moore, that manipulated him, lied to him, and eventually lost Chicken George in a bet that separated Chicken George from everything he knew.
The points you choose in your character's arc needs to be related by cause-and-effect. In the above sequence, Haley puts enough connections in each scene so they knit together. In the first two, Kizzy was a proud [for a slave] teen, the daughter of the ever defiant Kunta Kinte, sold as punishment and then brutally raped by her new owner (a drop from the peak of her own arc). The second point continues that arc, the result of the rape (and her own continued but muted defiance) is refusing to tell Chicken George who his real father is, and passing on her father's defiant attitude. In George as a child, this non-conformity rule-breaking manifests as a fun and entertaining kid.
Those two scenes seem a little unconnected from the 3rd, where he meets the slave Mingo, but Mingo is portrayed as a fright to the kids and it is George's independent streak that gives him the courage to stray off the path and engage with Mingo. So there is a connection there.
That leads into a straightforward set of scenes for George of a professional arc: a prodigy demonstrates skill, is promoted, promoted, promoted to the top. Then a single crucial failure and deception brings it all crashing down [not shown above].
Each scene is dramatized as another demonstration of surprisingly superior skill, in an escalation (hence the promotions). Along the way is a sub-arc of the other important element: romance. Haley's mission is not just to illustrate lives, but procreation. In Kizzy's case by violent rape, in George's case, he eventually finds love, marriage and children.
Your scenes should be connected, by cause and effect, action or reaction, or just ramifications of decisions. Event A results in Event B which results in Event C. Of course, George's conception is the beginning of his arc, so nothing he did caused it. But every child's arc grows from the intersection of their parent's arcs: His began due to Kizzy's defiance and bad luck of being sold (in anger by her previous owner) to Tom Moore, whose own arc (combined with greed and depravity) brought him to buy pretty young female slaves.
Your story is not "full of holes" if what you illustrate makes sense for what your character finally does. Readers accept that a full life is lived off stage, full of conflict, sex, disappointment, despair and heartbreak. You just need to ensure that if your character does something important to the plot, their ability and inclination to do that makes sense to the reader and is not an outcome out of nowhere. There should be a chain of justification in the previous scenes that make it, if not a predicted outcome, is at least a logically justified outcome.
For an example of an unpredicted by justified outcome, we have seen characters that are portrayed as consistent cowards, willing to save themselves by letting others die or suffer, ashamed but willing to do it again. But even cowards can love somebody, and if that love is shown in previous scenes of their arc, then when the coward is faced with personal death or the death of the one they love (a child, a spouse, a friend), their shame at all their previous cowardice may tilt them to a "not this time" moment in which they DO sacrifice themselves. (A similar arc is the fate of Fiddler, in the movie Roots).
Your story won't be full of holes if you sustain a thread between the scenes to tie them together.
