Regex expression does not work on version 10

Grafana
1

Hi everyone,

I’m currently facing an issue with a regular expression in Grafana. I’m trying to extract just the date from a timestamp like this: 2025-05-28T00:00:00.000Z

The regular expression I’m using is: ^(.?)T.$

In the Grafana Playground, this regex works perfectly - it matches the full string and captures just the date portion (2025-05-28) in group 1. However, when I try to use the same regex in Grafana version 10, it doesn’t seem to work as expected.

Has anyone encountered this behavior in version 10? Is there a change in how regex is parsed or applied between the Playground and the actual dashboard version? Or is there a workaround to reliably extract just the date from an ISO 8601 timestamp in Grafana 10?

Thanks in advance!

Image from playground

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image3574×922 96.5 KB

Image from v10

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image1877×337 27.9 KB

2

You can use units for that (override only for time column if you have several columns):

image
image1121×195 11.2 KB

Example of Units value:
time: YYYY-MM-DD

4

That solution does not work for my case. I dont want to force the format because i want to use datetime local to convert to MM-DD-YYYY or DD-MM-YYYY based on location

5

What is you datasource, may be it is better to do such type of conversion there?

6

The datasource column is on ISO format and at this moment changing the format is not an option

7

Hi, in your screen from v10 don’t you miss another .* after T in your regex?

8

Hi, thanks for the warning. I updated the screeshot showing that the corrected expression does not work. The previous screenshoot was showing an equivalente regex expression that also does not work on v10