Thời hạn đổi trả đến ngày mai.

Thời hạn means time limit, deadline, or valid period.

In this sentence, thời hạn đổi trả means the allowed period for exchanging or returning something. In natural English, that whole part could be understood as the exchange/return deadline or the return period.

Đổi trả combines two related retail actions:

• đổi = exchange
• trả = return

Together, đổi trả is a common store/business expression meaning exchange and return or returns/exchanges.

So thời hạn đổi trả is the period during which customers can exchange or return an item.

Vietnamese often leaves out a verb equivalent to is when the meaning is clear.

So:

• Thời hạn đổi trả đến ngày mai.

naturally means something like:

• The exchange/return deadline is until tomorrow
• The return period lasts until tomorrow
• The deadline is tomorrow

This kind of short, compact style is especially common in notices, labels, store policies, and announcements.

Literally, đến ngày mai means until tomorrow or up to tomorrow.

In context, it usually means the exchange/return period remains valid until tomorrow. In English, depending on context, you might translate it as:

• until tomorrow
• through tomorrow
• the deadline is tomorrow

A small nuance: Vietnamese can sometimes leave it slightly unclear whether it means by tomorrow or through the end of tomorrow. If someone wanted to be more explicit about through the end of tomorrow, they could say đến hết ngày mai.

It can suggest either idea, depending on context, but the core meaning is:

• the exchange/return period is valid up to tomorrow

In practical English, people may summarize that as:

• The deadline is tomorrow

If a business wants to be extra clear that customers still have all of tomorrow, they might say:

• Thời hạn đổi trả đến hết ngày mai.

That more clearly means valid through the end of tomorrow.

Vietnamese often puts the main topic first, then adds the time limit or description after it.

Here the structure is roughly:

• thời hạn đổi trả = the exchange/return period
• đến ngày mai = until tomorrow

So the sentence is built like:

• [Topic / thing being discussed] + [time endpoint]

That word order is very natural in Vietnamese, especially in short written statements.

Yes, đến and tới can both mean to / until in many contexts.

So you may also see:

• Thời hạn đổi trả tới ngày mai.

However, đến often feels a bit more standard or natural in written notices, while tới can feel a bit more conversational in some situations.

Both are understandable.

It is natural, but it sounds like written notice language rather than everyday conversation.

For example, a store sign or customer service message might say:

• Thời hạn đổi trả đến ngày mai.

In more conversational Vietnamese, someone might say something fuller, such as:

• Hạn đổi trả là ngày mai.
• Có thể đổi trả đến ngày mai.
• Thời hạn đổi trả còn đến ngày mai.

So the original sentence is correct and natural, especially in a retail or policy context.

Ngày mai simply means tomorrow.

In this sentence, native speakers would understand it as the relevant end point for the exchange/return period. They would not usually need extra words to understand the basic meaning.

But if precision matters, Vietnamese may add words such as:

• đến hết ngày mai = through the end of tomorrow
• trước ngày mai = before tomorrow
• trong ngày mai = during tomorrow

So ngày mai by itself is normal here, but it is somewhat context-dependent in exact timing.

A good breakdown is:

• Thời hạn = deadline / time limit / period
• đổi trả = exchange and return
• đến ngày mai = until tomorrow

So a natural overall understanding is:

• The exchange/return deadline is tomorrow.
• The return period lasts until tomorrow.
• Returns and exchanges are allowed until tomorrow.

Which English version is best depends on the situation, but the Vietnamese itself is compact and natural.