**At 2 years old, it’s normal not to understand “yesterday,” “today,” and “tomorrow” reliably.** Understanding time develops gradually; using the words can come before understanding their meaning.

A rough guide is:

- **Around 2–3:** Children begin using time words and understanding simple sequences—something happened already, or something comes next. “Yesterday” may mean almost any past event, and “tomorrow” may mean any future event.
- **Around 3–4:** Some understand yesterday and tomorrow when connected to their own experiences—for example, yesterday’s visit to Grandma or tomorrow’s outing. A recent study found this understanding in 3-year-olds, although abstract questions were harder. [Child Development study](https://doi.org/10.1093/chidev/aacaf019)
- **Through the preschool and early school years:** Understanding becomes more consistent, including that tomorrow becomes today, and today becomes yesterday. The precise meaning of “exactly one day ago/from now” can take longer to master. These are broad ranges, not deadlines. [Research on learning time words](https://www.sciencedirect.com/science/article/pii/S0010028516302079)

**Recognizing that life moves through routines comes before understanding days as calendar units.** Your child may anticipate meals, bedtime, or a familiar outing without yet understanding how many days have passed.

For now, make time concrete:

- “First we eat, then we go outside.”
- “Yesterday we went to the park. Today we’re staying home.”
- “Tomorrow, after your nighttime sleep, we’ll see Grandma.”

Use these naturally alongside familiar events, without expecting correct answers or testing them. At this age, mixing up the words is expected.