Here is the ICR astronomy link you provided
This is the most level-headed creationist article have ever read. Here is its conclusion:
*** So what is the state of creationist astronomy? We have seen that it has some good points to make. We have also seen that there have been some false starts and some problems. We must go beyond arguing what is wrong with evolutionary models. What is needed is an overall model or paradigm to describe the universe. A formation and history of the solar system must be explored. A particularly important question to address here is when and how the cratering that we see in the solar system occurred. Did the cratering occur during creation, at the fall, during the flood, or at some other time? A few authors have begun work on this question , . If we are not satisfied with stellar evolution, then we must provide physical arguments against it and supply our alternative. For the universe as a whole we must explain the light travel time in a plausible way.***
The main pointregarding the age of the universe is the last statement:
***For the universe as a whole we must explain the light travel time in a plausible way. ***
In the main body of the paper he indicates that the creationists do not have any plausible argument on how for example stars could be created on one day and the light get to Adam a day later.
So by their own admission they have failed to show that the universe could have been created in a day or even a week.
Personally I think it was created in an instant. But it took 10-20 billions of years before we humans got here to find that out.