Hello team! We have been using GrowthBook for a long time, but only today, all our experiment queries started failing out of the blue. We suspect this might be related to a bug somewhere in GrowthBook and we'd like to ask about that. When we check the queries, this is the error message that appears:

No matching signature for operator BETWEEN
  Argument types: TIMESTAMP, DATETIME, DATETIME
  Signature: (T1) BETWEEN (T1) AND (T1)
    Unable to find common supertype for templated argument <T1>
      Input types for <T1>: {TIMESTAMP, DATETIME} at [10:15]

Interestingly, this is an example of the line that causes the syntax error at BigQuery:

timestamp BETWEEN CAST('2026-01-14' AS DATETIME) AND CAST('2026-03-06' AS DATETIME)

However, if I recall correctly, queries generated by Growthbook used to cast dates as TIMESTAMP, not DATETIME, like this:

timestamp BETWEEN CAST('2026-01-14' AS TIMESTAMP) AND CAST('2026-03-06' AS TIMESTAMP)

Could someone please confirm whether this is caused by a recently-introduced bug on GrowthBook, or if we should change something on our side to fix it? Thank you!

Hi

That would be great! Thank you. Please don't hesitate to let me know if you have any further questions or comments.