It's a habit that is hard to break: projecting the expected time things will take in your day and making meeting this timeframe a condition of your contentment. In my experience this habit can and inevitably does cause significant anxiety, because none of us has control of all (or even most) of the factors determining how long things will take.
It's funny that although I've been in a state of wellness management for some years now, overcoming this unhelpful habit remains a challenge.
I point this out particularly for anyone reading who has anxiety issues (whether big or small) because it is so liberating to achieve the small wins over anxiety in our day to day. So when you go to bed in a hurry and think to yourself "must be asleep by 11:15pm", why not change the thought. Perhaps something like "I realise I am hopping into bed a bit later than planned. Probably won't be asleep quite as soon as hoped. No big deal."
One of my favorite quotes of all time is from the TV drama The Wire. A senior and a junior detective (called Lester and Prez) are conducting surveillance of a drug dealer's phonecalls (let's leave aside the ethics of this for another time!). Prez is tasked with recording which conversations are "pertinent" and which ones are not. After a while he tires of the task, and expresses his frustration.
Lester looks over the glasses resting on his nose and says to his junior: "we're building a case detective, and all the pieces matter".
So it is with getting a handle on anxiety. Every time we avoid a mistake that beset us yesterday (and perhaps every previous day of our life), we add a piece to our wellness. All the pieces matter.