For work, I just use the calendar for my work account. For personal stuff, I use the calendar that's built into my phone. I configure both to send me notifications before events. For large events, I will have multiple reminders in the days leading up to the event.
Alternatively, the places I've worked in the past typically have some sort of ticketing system. Deadlines can either be attached explicitly to a task or they can be implicitly tracked through sprints/cycles/etc. You may want to use something like this at work.
