They can exercice them at any time.  After September, they will need to pay more assuming they are exercised the following 12 months.

Each Unit consisted of one common share in the capital of the Company (a “Common Share”) and one-half (1/2) common share purchase warrant (a “Warrant”). Each whole Warrant will entitle the holder to purchase one Common Share for a two-year term, for an exercise price of $0.25 during the first 12-month period after the closing of the Offering and $0.30 during the subsequent 12-month period after the closing of the Offering. In the event that the 20-day volume weighted average price of the common shares listed on the TSX Venture Exchange is above $0.30 in the first 12-month period after the closing of the Offering, or $0.35 during the subsequent 12-month period, the expiry date of the Warrants may be accelerated, in whole or in part at the discretion of the Company, to any date or dates, as the case may be, that is 30 days after the first date such threshold is met.

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