`--execution-time` flag is ignored in `sqlmesh plan` only in prod (not in dev)

[michiel-de-muynck]

Actual behavior:

Given a model

MODEL (
    name sqlmesh_example.demo,
    kind INCREMENTAL_BY_TIME_RANGE (
        time_column day,
        batch_size 1
    ),
    start '2025-12-20'
); 
SELECT @start_ds AS day;

When running sqlmesh plan --execution-time '2025-12-26', the intervals between the model's start date and the execution time are filled (in this case 2025-12-20 until 2025-12-25) are created as expected.

However, subsequently running sqlmesh plan --execution-time '2025-12-28', sqlmesh does nothing, just stating:

No changes to plan: project files match the prod environment

This happens only in prod. If I do the same in dev environments, then the intervals 2025-12-26 and 2025-12-27 are filled as expected.

Expected behavior:

Since I explicitly pass --execution-time '2025-12-28', I expect the intervals 2025-12-26 and 2025-12-27 to be filled.

If this is somehow intended behavior, then at least I expect:

• dev and prod to behave the same way
• the documentation should mention this gotcha

Self-contained reproduction script:

# create temp dir for sqlmesh project
cd $(mktemp -d)
python -m venv .venv
source .venv/bin/activate
pip install sqlmesh

# create empty sqlmesh project with all defaults (duckdb)
yes 1 | sqlmesh init -t EMPTY

# create model
echo "\
MODEL (
    name sqlmesh_example.demo,
    kind INCREMENTAL_BY_TIME_RANGE (
        time_column day,
        batch_size 1
    ),
    start '2025-12-20'
); 
SELECT @start_ds AS day;
" > models/demo.sql

echo "Running in dev with --execution-time '2025-12-22'"
sqlmesh plan dev --execution-time '2025-12-22' --auto-apply

echo "Looking at the data:"
sqlmesh fetchdf "select * from sqlmesh_example__dev.demo"
# Note: this prints (as expected):
#           day
# 0  2025-12-20
# 1  2025-12-21

echo "Running in dev with --execution-time '2025-12-24'"
sqlmesh plan dev --execution-time '2025-12-24' --auto-apply

echo "Looking at the data:"
sqlmesh fetchdf "select * from sqlmesh_example__dev.demo"
# Note: this prints (as expected):
#           day
# 0  2025-12-20
# 1  2025-12-21
# 0  2025-12-22
# 1  2025-12-23

echo "Running in prod with --execution-time '2025-12-26'"
sqlmesh plan --execution-time '2025-12-26' --auto-apply

echo "Looking at the data:"
sqlmesh fetchdf "select * from sqlmesh_example.demo"
# Note: this prints (as expected):
#           day
# 0  2025-12-20
# 1  2025-12-21
# 0  2025-12-22
# 1  2025-12-23
# 0  2025-12-24
# 1  2025-12-25

echo "Running in prod with --execution-time '2025-12-28'. Should update the model (but doesn't)!"
sqlmesh plan --execution-time '2025-12-28' --auto-apply

echo "Note that the above incorrectly prints:"
echo "  No changes to plan: project files match the prod environment"
echo ""
echo "Notice the model still shows the only the days 20 to 25:"

sqlmesh fetchdf "select * from sqlmesh_example.demo"