Timestamp with influxdb and grafana

I am new to influxdb.Please help me with the following queries.
1.I need to plot process id details on grafana with influxdata.So I am using the timestamp.

Suppose the time is 2:10:33 PM(GMT) .I converted to epoch converter and got 1597327833000.Converted to ns 1597327833000000.

I added the following line in file.
insert newlog value=90 1597248978000000.

Is this usage correct?

But when I display in grafana it is showing as 1970 .Please help .Also confused with UTC,GMT,local time.

I have data from unix(pid data,with timestamp),and I need to plot in grafana.

Please help.