Unless specifically stated otherwise, all references to "days" in securities regulations are calendar days.
ZEN triggered the 45 day clock with their press release of June 1. The 45th calendar day following the press release is Thursday July 16.
The triggering of the clock is described in 4.2(1)(j). The expected follow-up is defined in 4.2(5)(a) and(b).
Lar
Here is the relevant text, abstracted from NI 43-101.
https://www.osc.gov.on.ca/en/SecuritiesLaw_ni_20110624_43-101_mineral-projects.htm
Obligation to File a Technical Report in Connection with Certain Written Disclosure about Mineral Projects on Material Properties
4.2 (1) An issuer must file a technical report to support scientific or technical information that relates to a mineral project on a property material to the issuer, or in the case of paragraph (c), the resulting issuer, if the information is contained in any of the following documents filed or made available to the public in a jurisdiction of Canada:
(j) any written disclosure made by or on behalf of an issuer, other than in a document described in paragraphs (a) to (i), that discloses for the first time (i) mineral resources, mineral reserves or the results of a preliminary economic assessment on the property that constitute a material change in relation to the issuer;
(5) Despite subsection (4), an issuer must
(a) file a technical report supporting disclosure under paragraph (1)(j) not later than
(i) if the disclosure is also contained in a preliminary short form prospectus, the earlier of 45 days after the date of the disclosure and the date of filing the preliminary short form prospectus; (ii) if the disclosure is also contained in a directors' circular, the earlier of 45 days after the date of the disclosure and 3 business days before expiry of the take-over bid; and (iii) in all other cases, 45 days after the date of the disclosure;
(b) issue a news release at the time it files the technical report disclosing the filing of the technical report and reconciling any material differences in the mineral resources, mineral reserves or results of a preliminary economic assessment, between the technical report and the issuer's disclosure under paragraph (1)(j).
