Date Math for a value 24 hours earlier

Hi,

I've got a query where I find the current value of a metric using date math of "gt"=> "now-2h" and I'd like to find the same value for this metric from the previous day (i.e. 24h ago).

What would that date math expression be?

Thanks

https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-date-format.html#date-math

does gt => now - 2d not working?