What time is it Lesson 1.8

Can anyone explain Lesson 1.8 What time is it: Xiànzài xiàwǔ liǎng diǎn。which translate into: Now it's 2 o'clock in the afternoon.
My question is why is it liǎng diǎn and not èr diǎn. I'm so confused and I've read through the lesson, and don't see anything explaining using liǎng diǎn. Xièxie nǐ!

The word "liǎng" is like the English word "a couple" and "èr" means two.  Whenever you are talking about time or numbers of objects (I have two bicycles), you use "liǎng" rather than "èr".

@Robert-C7 Makes so much sense.  Xièxie nǐ!

liǎng will always require a measure word followed by a noun, for example: wo you liǎng liàng zixingche (我有两辆自行车) ... I have two bicycles.
liàng (辆）is the measure word for vehicles.

I think the general rule is that if you have a count (one, two, three, four, ...) followed by a noun, you need a measure word or classifier between them.  However, when talking about time, you don't need a measure word between the time and diǎn, e.g.

现在下午两点
Xiànzài xiàwǔ liǎng diǎn