Timestamp now() function

[ilinardic22]

I would like to write an expression in which I check the time difference between the data I get in form of a Timestamp and the current moment.

The expression would look like: my_data_timestamp - time.now() < duration('1s')

Is it possible to write an expression like that in CEL? I could not find a CEL function that returns the current timestamp value, but could it be done by writing a custom function? I am using CEL with Java.

[TristonianJones]

The CEL team prefers not to introduce a now() function since its behavior might imply side effects, or that calling now more than once would possibly produce a different value.