How do I calculate my BTZ eligibility date?

Add 30 months to your TAFMSD (TIS threshold) and 14 months to your A1C Date of Rank (TIG threshold). Your BTZ eligibility date is whichever of these two dates is later — both must be met simultaneously. Then map that date to the nearest quarterly promotion cycle (January, April, July, or October).

Where do I find my TAFMSD?

Your TAFMSD is on your SURF (personnel data summary) available in vMPF (Virtual Military Personnel Flight). It's also on your promotion orders and your military ID record. If you're unsure, your unit's CSS (Commander's Support Staff) can look it up.

What if I was promoted to A1C later than expected?

Your A1C Date of Rank (DOR) is the date your A1C promotion took effect — not the date it was approved or when you started the paperwork. If your A1C DOR is delayed, your TIG threshold shifts forward correspondingly. Calculate from the actual A1C DOR shown on your promotion orders.

Why is TIS sometimes the binding constraint instead of TIG?

Most Airmen are promoted to A1C shortly after completing BMT (typically around the 6–12 month mark). Adding 14 months to A1C DOR gives a TIG date around month 20–26 of service, which is usually earlier than the 30-month TIS threshold. TIS becomes binding when your A1C promotion was relatively early in your service timeline.

How BTZ Is Calculated: USAF Below-the-Zone Promotion Formula

Learn how USAF BTZ eligibility is calculated from TAFMSD and A1C Date of Rank. Find your exact BTZ promotion quarter using the 30-month TIS and 14-month TIG thresholds.

Related Calculators

USAF BTZ Calculator
Estimate your normal Senior Airman date, six-month-early BTZ sew-on date, and likely quarterly promotion window.
Air Force Retirement Calculator
Estimate your 20-year active-duty retirement eligibility date and retirement multiplier.
Goat Gestation Calculator
Estimate a goat's kidding date and normal due-date window from the breeding date and an editable gestation-length assumption.
HYT (High Year of Tenure) Calculator
Estimate a projected HYT date from a service date and current authorized HYT limit.

The BTZ Calculation Formula

Below-the-Zone (BTZ) promotion eligibility is determined by two time-based criteria calculated from your service records:

Criteria 1 — Time in Service (TIS): 30 months from your TAFMSD (Total Active Federal Military Service Date) Criteria 2 — Time in Grade (TIG): 14 months from your A1C Date of Rank (DOR)

Your BTZ eligibility date = the later of these two calculated dates

Both thresholds must be met simultaneously for BTZ eligibility.

Step-by-Step Calculation

Step 1: Find your TAFMSD from your military SURF or personnel records. Step 2: Add 30 months to get your TIS-eligible date. Step 3: Find your A1C Date of Rank from your promotion orders. Step 4: Add 14 months to get your TIG-eligible date. Step 5: Take the later of the two dates — that's your BTZ eligibility date. Step 6: Map that date to the appropriate promotion quarter.

BTZ vs. Normal Promotion Thresholds

Threshold	Normal A1C→SrA	BTZ A1C→SrA
Time in Service	36 months from TAFMSD	30 months from TAFMSD
Time in Grade (A1C)	20 months from A1C DOR	14 months from A1C DOR

BTZ promotes Airmen exactly 6 months earlier than the normal timeline on both criteria.

Quarterly Promotion Cycles

Promotion Month	Eligibility Window
January 1	BTZ date falls Oct–Dec
April 1	BTZ date falls Jan–Mar
July 1	BTZ date falls Apr–Jun
October 1	BTZ date falls Jul–Sep

Example Calculations

Scenario A: TAFMSD = March 1, 2023; A1C DOR = August 15, 2023 - TIS: March 1, 2023 + 30 months = September 1, 2025 - TIG: August 15, 2023 + 14 months = October 15, 2024 - BTZ Eligibility: September 1, 2025 (TIS is binding) - BTZ Quarter: September falls in July–September → October 2025 promotion

Scenario B: TAFMSD = January 10, 2023; A1C DOR = November 1, 2023 - TIS: January 10, 2023 + 30 months = July 10, 2025 - TIG: November 1, 2023 + 14 months = January 1, 2025 - BTZ Eligibility: July 10, 2025 (TIS is binding) - BTZ Quarter: July falls in July–September → October 2025 promotion

Scenario C: TAFMSD = April 1, 2023; A1C DOR = January 1, 2024 - TIS: April 1, 2023 + 30 months = October 1, 2025 - TIG: January 1, 2024 + 14 months = March 1, 2025 - BTZ Eligibility: October 1, 2025 (TIS is binding) - BTZ Quarter: October falls in October–December → January 2026 promotion

What TAFMSD Means

TAFMSD (Total Active Federal Military Service Date) is the official start date of your active duty service. It's found on your military personnel record (SURF) and is typically your first day of basic military training (BMT). If you had prior military service, your TAFMSD may be adjusted to reflect total active service rather than your current enlistment start date.

Related Guides

Frequently Asked Questions

How do I calculate my BTZ eligibility date?: Add 30 months to your TAFMSD (TIS threshold) and 14 months to your A1C Date of Rank (TIG threshold). Your BTZ eligibility date is whichever of these two dates is later — both must be met simultaneously. Then map that date to the nearest quarterly promotion cycle (January, April, July, or October).
Where do I find my TAFMSD?: Your TAFMSD is on your SURF (personnel data summary) available in vMPF (Virtual Military Personnel Flight). It's also on your promotion orders and your military ID record. If you're unsure, your unit's CSS (Commander's Support Staff) can look it up.
What if I was promoted to A1C later than expected?: Your A1C Date of Rank (DOR) is the date your A1C promotion took effect — not the date it was approved or when you started the paperwork. If your A1C DOR is delayed, your TIG threshold shifts forward correspondingly. Calculate from the actual A1C DOR shown on your promotion orders.
Why is TIS sometimes the binding constraint instead of TIG?: Most Airmen are promoted to A1C shortly after completing BMT (typically around the 6–12 month mark). Adding 14 months to A1C DOR gives a TIG date around month 20–26 of service, which is usually earlier than the 30-month TIS threshold. TIS becomes binding when your A1C promotion was relatively early in your service timeline.

Last updated 7/28/2026