Aspects and Future time

Aspect is the form of a verb that shows whether the action happens once or repeatedly, is completed or still continuing. Thus, there are two aspects in English:

1. a perfect aspect
2. a progressive aspect

In grammar, tense is the time of a verb's action or state of being, such as present or past. It is marked by an inflection of the verb: 
Sarah drinks tea in the morning (present tense)
Sarah drank tea in the morning (past tense) 
There are multiple ways of expressing future time in English. Here are six of the most common methods.

1. the simple present: We visit our granny tonight.
2. the present progressive: We're visitingour granny soon.
3. the modal verb will (or shall) with the base form of a verb: O.K., I'll visit her.
4. the modal verb will (or shall) with the progressive: I'll be visiting my relatives in the summer.
5. a form of be with the infinitive: Sarah is to visit John at noon.
6. a semi-auxiliary such as to be going to or to be about to with the base form of a verb: We are going to visit John this afternoon.

Since the expression of future time does not involve any inflecton of the verb, we should not refer to a "future tense". Strictly speaking, there are only two tenses in English: present and past.