**At 2 years old, it is normal for a child to have only a partial understanding of “today,” “yesterday,” and “tomorrow.”** Understanding develops gradually, and children often start saying these words before they understand their meanings accurately. [Developmental research review](https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2018.02451/full)

A rough guide is:

| Age | Typical understanding |
|---|---|
| **2–3 years** | Begins using time words and distinguishing some things that happened from things that will happen. “Yesterday” and “tomorrow” are often used loosely. |
| **3–5 years** | Increasingly understands that yesterday is in the past and tomorrow is in the future. Correct use remains inconsistent. |
| **5–7 years** | Becomes more precise about which day an event happened and how days relate to each other. Understanding continues to improve through the early school years. |

These are broad ranges. Research finds that performance depends on the language a child speaks and how the question is asked. Understanding that “tomorrow is in the future” develops earlier than consistently understanding “tomorrow is exactly the next day.” [Study of children aged 3–7](https://pmc.ncbi.nlm.nih.gov/articles/PMC12594576/)

For **“Do they understand that days are passing?”**, the understanding emerges in pieces: remembering an event, anticipating another event, and learning how those events fit into successive days. A 2-year-old may remember a visit or anticipate a familiar activity while still being unsure which day it belongs to.

You can help by connecting time words to concrete experiences:

- “Yesterday we went to the park.”
- “Today we’re going shopping.”
- “Tomorrow, after your sleep tonight, Grandma will visit.”

For immediate plans, try “After lunch, we’ll go outside.” As your child gets older, a simple picture calendar can make successive days easier to discuss.

**Confusing these words at age 2 is expected.** Keep using them naturally; accurate understanding develops over the next several years.