Here’s what candidates generally find (and what GMAC officially states) about GMAT test dates, booking windows, and how early to reserve a slot—plus some real-world “availability” patterns.
How GMAT test dates work
• The GMAT is appointment-based (not fixed national test dates). You choose a test center or online, then select an available date/time in your mba.com account. 
Registration window: how far out can you book?
• GMAC’s Help Center states you can schedule test-center appointments up to 6 months in advance. 
• GMAC also notes that most test centers post appointments about six months out. 
So practically: you can usually see and book up to 6 months of slots, rolling forward.
How early should you book? (Practical guidance)
If you want the “best” slot (weekends / morning / specific center)
• Book 8–12 weeks ahead if possible, especially for Saturday slots—GMAC explicitly notes Saturday times fill quickly. 
If you’re flexible on day/time (weekday, afternoon, any nearby center)
• 3–6 weeks ahead is often enough.
If you’re late / want short notice
• Some candidates do find slots 1–2 weeks out, but it’s inconsistent and may mean odd times. Anecdotally, people report anything from “available in 2 weeks” to “booked for a month+” depending on the center. 
• GMAC also says availability changes frequently and recommends checking mba.com often. 
Online vs Test Center: what changes for booking?
• Online typically offers more scheduling flexibility than a single physical test center (because you’re not limited by seats). You still schedule through mba.com and can book up to 6 months out. 
• Test center availability varies by location and season; weekends fill faster. 
Important policy timing that affects planning
• Retake waiting period: you must wait at least 16 days between attempts. 
• Annual cap: online + test center combined, up to 5 attempts in a rolling 12 months. 
• Reschedule/cancel cutoff: changes can’t be made within 24 hours of the appointment; no-shows forfeit the fee. 
• GMAC also recommends planning to test 20 days before your program needs the score (buffer). 
A proven “booking timeline” most candidates use
1. Pick your target application deadline and work backward. 
2. Schedule your first attempt 6–10 weeks before you truly need the score.
3. Leave room for a retake: +16 days minimum + recovery/study time. 
4. If you need a Saturday slot: book as early as you can (8–12 weeks is a safe habit). 
5. If you’re not seeing slots: check frequently—openings appear as others reschedule/cancel. 
If you tell me your city/country and whether you prefer test center vs online (and weekday vs weekend), I can suggest a realistic “book-by” window (e.g., “book 10 weeks out” vs “3 weeks is fine”) based on typical slot pressure patterns.