I'm busy lately. I've been busy lately. more appropriate one
When you send someone a text message the idea is that it will sit there until someone has time to get to it. It is NOT like a phone conversation or an IM conversation where they expect you to be ready to answer right after they send a message. Anyone who gets an attitude over a late text response (a few hours to a whole day) is someone who is being very demanding. Even with my best and closest friend I don't apologize for a late text message response. Between the two of us we understand that we have busy lives and something as small as a text messages is easy to forget about. It is also important to remember that any time you apologize for ANYTHING, you are admitting that YOU did something wrong and you OWE them an apology. You don't owe anyone an apology for having your own schedule and responding to their message at your own pace. If it is a simple text message like, "can you pick up some milk?" then of course, you should respond in a timely manner and apologize if...