The FUTURE TENSE indicates that an action is in the future relative to the speaker or writer. There are no inflected forms for the future in English (nothing like those -ed or -s endings in the other tenses). Instead, the future tense employs the helping verbs will or shall with the base form of the verb: The future is also formed with the use of a form of "go" plus the infinitive of the verb: English can even use the present to suggest the future tense:
Note that the auxiliary will can be combined with "be" and a progressive form of the main verb to create a sense of the future that does not harbor any hint of insistence (which is possible with the auxiliary alone). For instance, if stress is placed on the word will in "When will you arrive?", the sentence can sound impatient, insistent. In "When will you be arriving?" there is less of that emotional overtone.

The construction form of to be + infinitive is used to convey a sense of planning for the future, command, or contingency.

To create a sense of imminent fulfillment, the word about can be combined with the infinitive. Other adverbs can be used in similar constructions with various effects:
Authority for this section: A University Grammar of English by Randolph Quirk and Sidney Greenbaum. Longman Group: Essex, England. 1993. Used with permission. Examples our own.