Per the IRS Instructions for Form 8949, page 5:

Stock acquired on various dates. If you sold a block of stock (or similar property) that you acquired through several different purchases, you may report the sale on one row and enter “VARIOUS” in column (b). However, you still must report the short-term gain or (loss) on the sale on Part I and the long-term gain or (loss) on Part II.

TaxAct® supports "Various" as the date acquired on Form 1099-B. Enter "Various" for the date acquired, then enter the cost basis, date sold, sales proceeds, and select either short-term or long-term.

To enter Form 1099-B for your capital gain or loss transactions in the program:

1. From within your TaxAct return (Online or Desktop) click Federal
2. Click Investment Income to expand the category, then click Gain or loss on sale of investments
3. Click Capital gain or loss (Form 1099-B)
4. Click New Copy of Form 1099-B (Desktop users click Add) to create a new copy of the form or click Review to review a form already created 
5. The program will proceed with the interview questions for you to enter or review the appropriate information