Two Years of Planning

Eisenhower's staff spent two years preparing for D-Day. The original date — May 1, 1944 — was pushed to June because they needed one more month of landing craft production. Eisenhower then delayed another 24 hours due to storms, overruling meteorologists who wanted a two-week postponement.

Group Captain James Stagg, the chief weather forecaster, identified a brief clearing window on June 6. Had Eisenhower waited, the next viable date with correct tides was June 19 — when the worst Channel storm in 40 years would have destroyed the invasion fleet on the beaches. Stagg's forecast and Eisenhower's nerve saved the operation before a single shot was fired.