Repeated confirming observations were made by IRAS at several timescales. HCON-1 represents the first sky survey made by combining repeated "hours- confirming" scans obtained at least 100 min and at most 38 hours apart over a period of 6 months. Another set of hours-confirming scans, interwoven with the HCON-1 scans but lagging by about 1 - 2 weeks, became HCON-2. HCON-3 data were obtained after the first 6 months of the mission, once hours-confirming surveys 1 and 2 were completed.