Most advice about competition preparation is written as though you have your evenings free and your weekends clear. Most candidates don't. Here's a plan that assumes a job, some obligations, and a finite amount of willpower.
You need roughly 60 to 120 hours of practice to move a reasoning score meaningfully. Working full time, you realistically have somewhere between five and twelve hours a week. That maths gives you eight to twelve weeks — which is why starting the week you hear about a competition matters more than any technique on this page.
The failure mode isn't lack of time. It's inconsistency: three hours on Sunday, nothing until the following Saturday, then guilt, then a fortnight off. Reasoning practice works through frequent repetition. Ninety minutes spread across three evenings beats four hours in one sitting, every time.
Weekday mornings (20-30 minutes, 3x per week). One short timed set before work. This is the highest-compliance slot for most people — nothing has gone wrong yet, nobody has asked you for anything, and your attention is intact. Abstract reasoning suits this slot well: short questions, fast feedback.