Back in the olden days (before we made aliyah), when I’d go over to my parents’ apartment around Elul time, my dad z”l would pull out all the Jewish calendars he’d received in the mail that month; then he’d proceed to try to unload as many as he could on me.
We haven’t had a Jewish calendar in years. I get emails every Thursday (or before a chag) from 3 shules in the area, and all the times we need are in the emails. I make up an Excel schedule of all the davening times, candle time, and end of Shabbat time, and post it on our fridge. I can find whatever minyan I want at a particular time. I don’t need text message reminders.
I daven mincha g’dola at a fixed time pretty much every weekday, so I don’t need a calendar for times. Arvit is a fixed time year round, so I don’t need times for that either.
For date conversions I have hebcal.com bookmarked.