To find the answer, first add 30 to 45, resulting in 75. Since an hour has just 60 minutes, we need to subtract 60 from 75, which leaves a remainder of 15. So we need to add one hour to 12, resulting in 13 o'clock or 1 PM. Adding the 15 minutes left as a remainder gives the final answer: 13:15. So 30 minutes after 12:45 is 13:15 (1:15 PM)., Use this hours ago calculator to find the exact time a set number of hours ago, from now, or from any custom reference time., Here's a step by step guide on how to use the Data and Time Calculator in order to Add Date and Time: On the topmost part of the calculator, you can find the ⚙️ Operation Type field set. It is where you need to choose from the operation options - add, subtract and duration between., Calculate time and date difference in time and days between 2 date times. Find date difference with future or past dates and times. Use United States, European or ISO date formatting. Calculate days for contracts, shipping, business agreements, birth dates, age, etc., Time calculator - Find past/ future clock time by subtracting/ adding hours and minutes respectively. Get answer to questions like "what time will it be in 8 hours?" "what time was it 45 minutes ago?", Convert dates and times across multiple time zones with our advanced, user-friendly calculator. Perfect for international business, travel planning, and more..