Geirfa Dyddiadau/Rhifau
Rhifau
| Rhif | Number | |
| Rhifau | Numbers | |
| Un | 1 | |
| Dau | 2 | |
| Tri | 3 | |
| Pedwar | 4 | |
| Pump | 5 | |
| Chwech | 6 | |
| Saith | 7 | |
| Wyth | 8 | |
| Naw | 9 | |
| Deg | 10 |
Diwrnod yr Wythnos
| Dydd | Day | |
| Diwrnod | Day | |
| Wythnos | Week | |
| Penwythnos | Weekend | |
| Pythefnos | Fortnight | |
| Mis | Month | |
| Blwyddyn | Year | |
| Dydd Llun | Monday | |
| Dydd Mawrth | Tuesday | |
| Dydd Mercher | Wednesday | |
| Dydd Iau | Thursday | |
| Dydd Gwener | Friday | |
| Dydd Sadwrn | Saturday | |
| Dydd Sul | Sunday |
Misoedd
| Ionawr | January | |
| Chwefror | February | |
| Mawrth | March | |
| Ebrill | April | |
| Mai | May | |
| Mehefin | June | |
| Gorffennaf | July | |
| Awst | August | |
| Medi | September | |
| Hydref | October | |
| Tachwedd | November | |
| Rhagfyr | December |
Dyddiad
| Dyddiad | Date | |
| Y cyntaf [1af] o.. (e.e.Ionawr) | The first of.. (e.g.January) | |
Yr ail [2il] o.. |
The second of.. | |
| Y trydydd [3ydd] o.. | The third of.. | |
| Y pedwerydd [4ydd] o.. | The fourth of.. | |
| Y pumed [5ed] o.. | The fifth of.. | |
| Y chweched [6ed] o.. | The sixth of.. | |
| Y seithfed [7fed] o.. | The seventh of.. | |
| Yr wythfed [8fed] o.. | The eigth of.. | |
| Y nawfed [9fed] o.. | The ninth of.. | |
| Y degfed [10fed] o.. | The tenth of.. | |
| Yr unfed ar ddeg [11eg] o.. | The eleventh of.. | |
| Y deuddegfed [12fed] o.. | The twelfth of.. | |
| Y trydydd ar ddeg [13eg] o.. | The thirteenth of.. | |
| Y pedwerydd ar ddeg [14eg] o.. | The fourteenth of.. | |
| Y pymthegfed [15fed] o.. | The fifteenth of.. | |
| Yr unfed ar bymtheg [16eg] o.. | The sixteenth of.. | |
| Yr ail ar bymtheg [17eg] o.. | The seventeenth of.. | |
| Y deunawfed [18fed] o.. | The eighteenth of.. | |
| Y pedwerydd ar bymtheg [19eg] o.. | The nineteenth of.. | |
| Yr ugeinfed [20fed] o.. | The twentieth of.. | |
| Yr unfed ar hugain [21ain] o.. | The twenty-first of.. | |
| Yr ail ar hugain [22ain] o.. | The twenty-second of.. | |
| Y trydydd ar hugain [23ain] o .. | The twenty-third of.. | |
| Y pedwerydd ar hugain [24ain] o.. | The twenty-fourth of.. | |
| Y pumed ar hugain [25ain] o.. | The twenty-fifth of.. | |
| Y chweched ar hugain [26ain] o.. | The twenty-sixth of.. | |
| Y seithfed ar hugain [27ain] o.. | The twenty-seventh of. | |
| Yr wythfed ar hugain [28ain] o.. | The twenty-eighth of.. | |
| Y nawfed ar hugain [29ain] o.. | The twenty-ninth of.. | |
| Y degfed ar hugain [30ain] o.. | The thirtieth of.. | |
| Yr unfed ar ddeg ar hugain [31ain] o.. | The thirty-first of.. |