If this has worked for you, then by all means keep doing it. However, in all my years of dating and being in relationships (including the woman I'm engaged to now), I've gotten far more yeses for dates by NOT asking what their schedule is.
I frame my ask the way I said the OP should do it: I tell them I want to take them out, and I give them the option of 2 days that I'M available. Now, if she can't do either days that's fine and she's free to suggest a day that would work better... but why do I do it this way?
Simple: because I want HER making time for a date based on MY schedule, not hers.
It's a power dynamic play. Of the two of you, you should be the leader, which is what she wants you to be. Therefore, she should be trying to fit her life into YOUR schedule (i.e. follow your lead and when YOU have time for her), not the other way around.
You give them the option of 2 days so it makes them feel like they have power of choice. That also lets them know you're free more than one day, so if those days don't work for her you're possibly open to another day.
This is just one small example of communication dynamics that men don't understand. For women, who are great at picking up passive language and social cues (as a generality), you don't have to spell out everything for them in order to have good communication. In this case, you don't have to use word salad to get them on a date by saying ALL the things like "hey I want to take you out and I want to make sure you're ok with where we go and what we do and oh by the way can you check your schedule to see if you can fit me into it?"
Less words = more power. "Hey, we should get drinks, I'm free Tuesday or Thursday, lmk".
Lastly, the real reason asking her schedule is a waste of time is because WOMEN WILL ALWAYS BREAK THEIR SCHEDULE FOR MEN THEY LIKE. And for men they don't like, they'll bring up a scheduling conflict of their own accord. Either way, it again means you don't have to ask them about it because their answer to you will let you know if they feel you're worth their time.
This is a hypothetical outcome tree of how the
texting would be if you asked for her schedule and didn’t?
Scenario 1 (asking for her schedule):
Clockwerk50: How's your schedule looking this weekend?
Her: I don't have anything planned, I might be busy, why?
Clockwerk50: We should get drinks together this weekend.
Her: I can't, my grandma is sick. I have to go see her.
Scenario 2 (asking for her schedule):
Clockwerk50: How's your schedule looking this weekend?
Her: I don't Mr. Clockwerk, how about you?
Clockwerk50: We should get drinks together this weekend.
Her: Yes, for sure! I can't wait
Scenario 3 (giving two options):
Clockwerk50: Hey, we should grab drinks. I'm free Tuesday or Friday, let me know.
Her: Not sure, my friend might want to schedule something. I'll let you know!
Scenario 4 (giving two options):
Clockwerk50: Hey, we should grab drinks. I'm free Tuesday or Friday, let me know.
Her: Yes, for sure! Le & know what time.
Scenario 5 (she makes herself accessible):
Her: Hey Clockwerk, I have something to do this weekend but let me know if you can meet so l can cancel it.
Her level of interest dictates the outcome, not the wording. If she likes you, she'll make time - if not, she'll flake or stall. Asking for her schedule doesn't mean you're not leading, you still have to propose a date and plan.
Remember, seduction is the process of drawing people in, making them want to peruse you and possess you. If women are not trying then you are doing something wrong.