T12M

T12M provides the broadest and most holistic time window used in Amazon analytics.
Unlike fixed calendar years, T12M always reflects the last 365 days, updating daily.
This makes it ideal for understanding true year over year performance, smoothing out seasonality, promotions, and short term anomalies.

Where T12M is commonly used:

• Annual vendor scorecards
• Long term sales and profitability analysis
• Category benchmarking and strategic planning
• Forecasting and demand modeling
• Pricing and margin studies
• Inventory health evaluation (OOS, STR, overstock)
• Advertising performance comparison across seasons

Why T12M is powerful:

• Captures all seasonal peaks (Prime Day, Q4, T5/T12)
• Includes full product life cycle trends
• Reduces impact of short lived events like deals or temporary OOS
• Helps Amazon and vendors identify structural growth or decline
• Essential for planning ABAs, trade terms, and budget cycles

Example:
If today is November 10, 2025, the T12M period covers November 11, 2024 through November 10, 2025.
A vendor reviewing T12M shipped revenue can see the full effect of Prime Day, back to school, and Q4 holiday performance within one integrated view.

What T12M helps diagnose:

• True year over year growth trajectory
• Whether demand is seasonal or consistent
• How promotions affected annual performance
• Long term shifts in category competitiveness
• Sustainable impact of pricing and advertising changes

Benefits for Sellers and Vendors:

• Reliable long horizon insights for strategic planning
• Improved ordering and forecasting accuracy
• Visibility into brand health across full cycles
• Stronger understanding of product life cycle trends

Benefits for Amazon:

• More accurate long term category modeling
• Smarter PO and FC capacity planning
• Better evaluation of vendor performance for AVS and RBS teams

In short:
T12M (Trailing 12 Months) is the rolling 12 month period Amazon uses to assess long term sales, traffic, advertising, and inventory performance, providing the clearest view of true business trends.