The time to buy clothes of course is when they're not needed, because by the time they're needed it's too late. At least, it's too late in the sense that a man's only choice will be to buy off the rack clothes that probably won't fit very well (an off the rack shirt is a terrible thing on me, perhaps exceeded only by shoes that raise blisters).
Consider the lead times required to have clothing made:
- Shirts, two to three months if there's already a perfected pattern and twice as long if there isn't
- Tailored clothing, two to twelve months depending on how often customer and tailor are in the same city
- Shoes, about five months for made to order shoes and five to twelve months for bespoke shoes
So when is the best time to buy clothes? Probably when a man looks in his closet and thinks to himself that he has everything he needs. That's a leading indicator that some form of calamity is about to befall his wardrobe and he'd better order something.