<p>Organisms live their own spacetime. How do they measure it? Obviously, living beings must assess what to do in time and estimate how to take an action in space. This paper contributes to a theoretical examination of the nature of spacetime, whereby spacetime is considered a meaning-making system and is produced in communication codes instead of being given as an independent physical reality. When organisms in interaction coadjust their timing with each other and bring about mutual social space, spacetime is said to be in the <i>E</i>-series. Unlike the <i>B</i>-series (third-person) code, which drives humans to see spacetime as physically existing, permitting the quantification of the extent in space and time, the interactive spacetime in the <i>E</i>-series (second-person) code might look foreign to such a measurement owing to its qualitative, nonverbal, and ever moving characteristics. This paper aims to expand the epistemic horizon of measurement to include nonquantitative scientific inquiry within the realm of measurement.</p>