Fixed time range for grafana variables

I have a dashboard variable that i’m getting its values from elastic-search and the time-range of getting them is the same time-range of the dashboard itself. However when i don’t have data logged for a specific variable it will not appear in the variable result which is not the preferred outcome
so is there anyway i can fix the time range of the query to be last 7 days as an example or last month?
here is the query i use
{“find”: “terms”, “field”: “sysloghost.keyword”, “query”: “”}