I’d definitely second this! We need the ability to map things to sprints but our sprints are in a different table so we need to use lookups to get the sprint dates

Welcome to the community @Brook_Warner

Thanks for seconding this and with your similar use case too.

I looked at the new Gantt block and it’s not suited to the use cases of timeline visualisation we have. So hopefully this lookup to dates can work in the Timeline block.

I found a workaround. Create a new field, I called mine “calculated end date”, and make it a formula field. Put it ={end date} and suddenly timeline works!

t2: that’s a great workaround. Thank you @Brook_Warner I’ll go add the formula field to our instance. Nice t2:

Another (ultimate?) workaround: Instead of a Lookup field, use a Rollup field with an aggregate function that guarantees a single result.

For instance, I’m using a Rollup of a “Deployed” field, and the MAX(values) aggregate function. In our case, all the Deployed dates in the linked records are the same, so the MAX(values) function would give the same result as MIN(values). Either way, MAX() and MIN() always return a single result. ARRAYJOIN(values) won’t work as this concatenates multiple dates into a string.

Importantly, MAX() and MIN() are aggregate functions that return a single result, a single date. A Lookup field could easily return multiple dates. This may be why Lookup can’t be supported for the Timeline block - it needs to be sure of a single date for the Start date field and End date field.

I think this understanding means we ought to close this forum thread. Thank you @Brook_Warner for helping reach this understanding. t2: