予定だis scheduled to; is due to
It is on the schedule: a date is set, a ticket booked, an announcement made. English says "is scheduled to" or "is due to". Of your own plans it says "I'm planning to", the phrase it uses for つもり; with 予定 the thing is arranged.
your own plan
I am planning to travel to Kyoto next month.
a schedule
This train is scheduled to arrive at 9:10.
with a noun
The next interview is scheduled to last one hour.
With a verb
Verb dictionary form + 予定だ
行く予定です. Not going to: 行かない予定です. The verb stays plain and です comes once, at the end.
With a noun
Noun + の + 予定だ
A time, a length of time, or the event itself: 三時の予定です, 一時間の予定です, 出張の予定です.
What is on the schedule
You hear it in station announcements and on the news, and say it about anything on your own calendar. It reports what has been arranged and promises nothing: plans change.
According to the city's announcement, the new library is scheduled to open in October.
I am not planning to return to my country at the end of the year.
Tomorrow's training session is scheduled to run until 4 p.m.
A schedule is a fact anyone can know. So you can say what someone else is due to do, and ask about their plans without prying.
The department manager is scheduled to go to Osaka on business next week.
When are you planning to come to Japan?
予定 or つもり?
つもり is what you have made up your mind to do. 予定 is what is on the calendar. A train or a meeting can't make up its mind, so it only takes 予定.
I intend to study abroad in Japan next year.
You have decided. Nothing need be arranged yet.
I am due to study abroad in Japan next year.
It is arranged: the school and the dates are set.
Not said: 会議は
(The meeting is due to start at three.)
始まる予定です.
予定 by itself: plans
予定 is also the everyday word for "plans". 予定があります is "I have plans", and a gentle way to turn an invitation down.
Do you have any plans on Saturday?
Sorry, I've got plans on Saturday…
Close neighbours
ようと思っているN4
"I've been thinking of": in mind for a while, nothing fixed.
When spring comes, I am thinking of going to Kyoto to see the cherry blossoms.
ことになっているN4
What has been laid down, often by someone else. A standing rule takes this, not 予定.
You're not supposed to use cell phones during exams.
はずだN4
"Should": what you expect from what you know. 予定 is the plan itself.
According to the schedule, the train should arrive at ten.
Check yourself
1Which one fits?
飛行機は
Choose an answer to see why.
2Which one fits?
来月、
Choose an answer to see why.
3You have a lot on this week. Which fits?
Choose an answer to see why.
More detail
予定だった
In the past it is usually a plan that changed: "was supposed to".
I was supposed to arrive at three, but the train was late.
予定どおり
予定どおり is "as planned" or "on schedule".
The plane arrived on schedule.
On boards and in headlines
There 予定 goes straight onto the noun: 到着予定 (due to arrive), 発売予定 (due for release).
More sentences
The information session is scheduled to begin at ten in the morning.
The new product is scheduled for release in June.
The meeting at the branch office is scheduled for next week.
The construction work is scheduled to be completed next March.
Because of work, I'm not planning to join the online meeting this time.