The phrase "distance in time" refers to the amount of time that has passed between two events or moments. Some common synonyms for this term include "duration", "interval", and "span." Other options might include "elapsed time," "time lapse," or "timeframe." When discussing historical events or periods, you might use terms like "era," "epoch," or "age" to refer to a longer period of time. Alternatively, if you want to emphasize a specific timeframe or deadline, you might use words like "deadline," "target date," or "due date" instead. Ultimately, the choice of synonym will depend on the specific context and the tone of your writing or conversation.