Hybrid Search Date Filter Ignored When No Matching Data in Range?

Hi, i’m running into unexpected behavior when combining hybrid search with a date-range filter. When I filter for a range in which no objects exist, the filter seems to be silently dropped and I get back all results—as if no filter were applied. However, when I filter for a range that does contain data, the filter works correctly.

I’m using the Python client and have a class ArtikelChunks with a publishdate property (DateTime). All of my data live in March 2025.

Here a code sample to reproduce:

import datetime
import weaviate
from weaviate.classes.query import Filter
from zoneinfo import ZoneInfo

start_date = datetime.datetime(2025, 5, 1).replace(tzinfo=ZoneInfo("Europe/Berlin"))
end_date   = datetime.datetime(2025, 5, 15).replace(tzinfo=ZoneInfo("Europe/Berlin"))

if start_date.date() == end_date.date():
    next_day = start_date + datetime.timedelta(days=1)
    date_filter = (
        Filter.by_property("publishdate").greater_or_equal(start_date)
        & Filter.by_property("publishdate").less_than(next_day)
    )
else:
    date_filter = (
        Filter.by_property("publishdate").greater_or_equal(start_date)
        & Filter.by_property("publishdate").less_or_equal(end_date)
    )

client = weaviate.connect_to_local(headers={"X-OpenAI-Api-Key": embeddings_api_key})
chunks_collection = client.collections.get("ArtikelChunks")

response = chunks_collection.query.hybrid(
    query="whatever",
    limit=5,
    filters=date_filter,
)

print("Start Date:", start_date)
print("End Date:  ", end_date, "\n")

for o in response.objects:
    print("publishdate:", o.properties.get("publishdate"))

client.close()

Output for May 1–15, 2025 (no data in that window):

Start Date: 2025-05-01 00:00:00+02:00
End Date:   2025-05-15 00:00:00+02:00

publishdate: 2025-03-05 06:23:00+01:00
publishdate: 2025-03-12 14:30:00+01:00
publishdate: 2025-03-18 09:15:00+01:00
publishdate: 2025-03-26 17:50:00+01:00
publishdate: 2025-03-30 22:05:00+01:00

… (all March dates)

Output for Mar 1–15, 2025 (data exists):

Start Date: 2025-03-01 00:00:00+01:00
End Date:   2025-03-15 00:00:00+01:00

publishdate: 2025-03-13 18:46:36+01:00
publishdate: 2025-03-09 18:00:00+01:00
publishdate: 2025-03-14 16:22:09+01:00
publishdate: 2025-03-01 09:02:00+01:00
publishdate: 2025-03-09 19:12:10+01:00

… (correctly only March 1–15)

Questions

1. Is it expected behavior that when a hybrid query’s filter matches zero objects, the filter is ignored and all objects are returned?
2. If not, how can I enforce a “no-matches → empty result set” semantic when filtering on a date range with hybrid search?

Any pointers or workarounds would be appreciated.

Server Setup Information

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• Deployment Method:
• Multi Node? Number of Running Nodes:
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