Timedelta as delta in go.Indicator

Hi, dear Plotly Dash community! I am a relatively newbie (about a month) and I’m not native in English, so please forgive in advance for possible grammar errors.
I have two sales agents doing similar jobs (closing a deal), and wanted to compare them by duration of doing job.

I can compare their duration in seconds and get delta in percentage, but I want absolute difference in timedelta. Is that possible?

Sample code is below:

agent_one_duration=agent_one_end_time - agent_one_start_time #(two variables in pandas datetime64[ns] dtype)
agent_one_duration_in_seconds=agent_one_duration / np.timedelta64(1, 's')

similar algorithm for agent_two and then:

fig = go.Figure()

    mode = "delta",
    value = agent_one_duration_in_seconds,
    delta = {'reference': agent_two_duration_in_seconds, 'relative':True, 'valueformat':'.1%'},