This show ran from 1968 until 1973, and I hadn't seen it on TV probably since its initial run until the DVDs came out. The show aired at a time when American culture was going through a great transition. When Doris Day first went on the air Bonanza and The Andy Griffith Show were the top television draws. By the time it went off the air it was All in the Family and M.A.S.H. Thus it is amazing that Doris Day stayed on the air for five years during this time when her clean-cut image probably set her apart from the crowd, and then walked away from her show - the show was not canceled due to poor ratings. In fact, it did quite well throughout its run.
It will take you back to a simpler time, but then so did Doris Day's films and I still find those enjoyable. The show did make major changes to accommodate the changing times. Initially it had a rural setting with Doris being a widow with two sons who played a major part in the show. First the show had her moving to San Francisco. Next she and her sons moved to a more "hip" apartment. By season four the kids and her widowhood status had disappeared and she was single. Her father and her sons just vanished into thin air, never to be mentioned again.
Also, Doris evolved from a secretary to an associate editor. However, she kept her name and the second apartment she had when her sons had existed. It was very confusing. I'd still recommend it, just remember that culture changed so fast in the U.S. during this time that it even had an effect on how Doris Day was presented.