With your personal light cone, it's fine to equate "now" with what you see in the moment. It just has to be clear what you mean for situations where communication might be ambiguous. If you have a person on mars, be sure to be precise what you mean when you tell them to do something in five minutes, when they receive the message they won't know if you mean five minutes after they receive the message or anywhere between 17 minutes before and 2 minutes after they receive the message.
When you get into relativistic speeds (and especially very short time intervals), nobody can even agree on when something "actually" happened, different observers have different opinions about what happens when even after you account for light travel time.
