diff --git a/src/all_sequences/base_sequences.jl b/src/all_sequences/base_sequences.jl
index b6b4bbeb3a152c310a8a198f5eb85022807e68ad..4c6df22074f2194a6239094a570eacdb3d4f9850 100644
--- a/src/all_sequences/base_sequences.jl
+++ b/src/all_sequences/base_sequences.jl
@@ -38,7 +38,7 @@ function start_time(bs::BaseSequence{N}, index::Integer) where {N}
         throw(BoundsError(bs, index))
     end
     base_index = ((index - 1) % N) + 1
-    base_time = sum(i -> duration(bs[i]), 1:base_index)
+    base_time = sum(i -> duration(bs[i]), 1:base_index-1; init=0.)
     if iszero(nTR)
         return base_time
     else