Assign earliest and latest _time to some other timestamp column

[splunk_hvijay]

I want to take the earliest and latest _time and assign to some other timestamp column. For example, I have a timestamp column Transaction Date which is NOT _time and I want to use this in the search command to achieve the below

Index = test | where Transaction_date => earliest and Transaction_date <= latest

Can you please help me.

Not sure what is epoch time and why to convert that. I have timestamp like "2016-08-05 12:00:00.0"

[richgalloway]

Try this

index=test | addinfo | eval Tdate=strptime(Transaction_date,"%Y-%m-%d %H:%M:%S.%1N") | where Tdate >= info_min_time AND Tdate <= info_max_time | ...

Epoch time is the Unix timestamp standard. It's the number of seconds since 1 Jan 1970 (IIRC). Converting dates to epoch (integer) form makes it vastly easier to compare and manipulate them.