I want to learn and include the temporal relationship alongside my variables at each time series instance.

And I learnt that previously they used models to represent all variables by a single variable or reduce the dimensionality of variables.

I read also they created a variable for time indexing which include first difference values of time, ex. for first instance its T2-T1, and i want to know more techniques to include temporal relationship as a variable or by any means before feeding my dataset to clustering algorithms. Do you know any other techniques to represent this as a feature or by transforming existing feature to include temporal/spatial pattering , or what they call it inter/intra patterns?