There are several synonyms for the term "this day," which can be used to add variety and precision to your writing. One option is "today," a common and straightforward alternative. Another possibility is "the present day," which conveys a sense of current or contemporary circumstances. "The current date" offers a more specific and formal option, useful for reports or official documents. "The twenty-four hours" or "the day cycle" are more technical alternatives, suitable for discussions of time management or scientific research. In poetic or creative writing, one could use "the now," "the moment," or "the present moment" to add an air of immediacy and significance to the phrase.